Urban Ethology

Cultural exchange

2010-08-24T11:41:00.000-07:00

Since getting back from Israel, I've taken a break from the monkeys this summer to work with crows, instead. It might sound like a drastic change, but crows and primates are more similar than you might expect. Both are fairly long lived, social animals, with extended family groups. Both crows and monkeys keep track of siblings, half siblings, uncles, aunts, grandparents... and they know who's who! Several studies have shown that both of these animals show kin selection - they treat close relatives better than distant relatives ("I'll share that food with my little brother before I share it with a cousin!"), and distant relatives better than total strangers. Some animal behaviorists suspect that it's this social-ness that's responsible for their other similarity: both the birds and the monkeys have surprisingly complex cognitive abilities. (But I don't need to remind you loyal readers of that - I've mentioned crows' amazing tool use abilities, monkeys' ability to manipulate social situations, and many others in the past!) For those of you who don't want to dig through past posts, I'll just restate the simplified argument: some biologists believe that having to keep all those family relationships straight, not to mention manipulating them (remembering who shared food with you last week, and who was stingy, for example) naturally leads to the evolution of bigger brains.

It turns out that there's another similarity between crows and monkeys: given the overlapping generations in both animals, the cognitive and problem solving abilities, and the tool use, both can be described as having "culture". Of course, this is one of those loaded terms that sends anthropologists into fits, but I'm not going to debate its application to animals here. Assuming that animals can have "culture" - by which I mean learned behaviors that are transmitted from one generation to another- then both crows and monkeys qualify, as well as several other types of animals, especially whales and dolphins. To those of us who accept that animals can have culture, the claim that corvids (ravens and crows) are included on this list isn't terribly shocking. But here's an idea that was new to me: not only can crows have culture, they can exchange cultural ideas with human cultures! We think of cultural exchange among human groups - like groups that met and traded along the Silk Roads , but perhaps cultural exchange can also occur between species.

I came across this idea in my summer crow research. I've been studying an endangered species that lives on Pacific islands, trying to figure out why these birds are disappearing. One of the factors that almost certainly contributes to their decline is the fact that humans hate the birds - even though it's illegal to harm an endangered species, it's pretty common for people to shoot the crows they see on their land. In trying to understand why humans feel so much antagonism towards crows, I stumbled on this article, by John Marzluff and Tony Angell, that describes how crow and human cultures shape each other. The authors' ideas about "cultural co-evolution" take the idea of influence one step farther: not only are our cultures responding to each other, but those cultural influences are actually changing our evolutionary paths. That is, the effect of cultures is playing out on the genetic level.

An example from the paper is the millenia-long interplay between crows and farmers. This is especially true in areas where humans have grown corn. Crows steal corn, and farmers have to develop new and better ways to keep them away. Most famously, this has resulted in the invention of the scarecrow, although farmers also use a number of other methods, including wind-powered noise makers and automatic cannons to keep the birds away. The problem is that crows, being intelligent animals, quickly get used to whatever scary-devices the farmers think up, so farmers must be creative. The cultural interplay here is obvious: the farmers think up crow-scaring devices, knowledge which they pass on to their friends and children. The crows learn which devices are harmful and which are harmless, and how to circumvent the farmers' efforts. Evidently, they also teach each other this information.

The cool part, what I had never thought of before, is that the interplay may also be genetic. If you think about it, scare-crows are really selecting for bolder and shrewder crows - crows that can figure out what really poses a threat and what's just a "straw man". On the other hand, thieving crows selects for more creative, and observant human farmers - farmers who can figure out what tricks a crow and what doesn't, and who are able to adapt quickly as the crows habituate. If either side is too slow or too stupid, they won't by eating - which could lead to their genes falling out of the gene pool. Basically, crows and humans are both pushing each other to be smarter and wilier. So before we congratulate ourselves too much on being the smartest animals in the pack, we should acknowledge the other animals who've helped us get here through coevolution!

The article also has some other cool examples of animal-crow coevolution - for example, patterns of human driving and crow use of roads to crack nuts. However, I never found exactly what I was looking for - I'm still not sure why there is so much prejudice towards crows, unless it's that humans dislike an animal that can outsmart us. If any of you have any answers to my question, please help me out!

City of peace?

2010-07-10T04:58:00.000-07:00

Hey there everyone, sorry I've been M.I.A. for so long. The end of the quarter hit me hard in May, and I left almost immediately after for Israel. I just got back from my trip a couple of days ago, so now I'll try to catch you up with some of the ideas I've been thinking about in the last two months... but first, a few thoughts about our time in Israel. Or, one thought in particular : a perspective on the conflict in the Middle East (given my new "expert" status after being there for 3 weeks).

Jerusalem, ironically enough, comes from the words "Yeru shalom" - "city of peace". From a historical perspective, this name is pretty laughable - Israel, and Jerusalem in particular, have been the source of conflict and war for thousands of years now. But, within a shorter time frame - on any given day, for example - it is amazing how well so many people coexist in such a small space. The old city of Jerusalem, is officially sectioned off into the Christian quarter, the Jewish quarter, the Muslim quarter, and the Armenian quarter, but these distinctions seem to apply mostly to the types of souvenirs sold on any given street. In reality, the city is a total hodge-podge of religious sites, with temples built on top of tombs, churches sandwiched between mosques, and pilgrims of all types crowded in the streets. The call to prayer competes with the ringing of church bells and the yells of street vendors, and at any given moment, you can see groups of Hassidic Jews, Indian Christians, Somalian Muslims and Brazilian tourists in short-shorts, all touring the same square. Really, it's amazing that there isn't daily bloodshed on the streets!

As vibrant as the city is, it's hard to understand why so many people have given their lives over the years for a bunch of hot stones and dust. Personally, I think that there must be some kind of magic or madness involved - why die for a piece of land where not even an olive tree will grow? It turns out that clinical psychologists agree with me: there may be some kind of madness at the core of it. Psychologists recognize a specific mental disorder called "Jerusalem Syndrome", wherein visitors to that city experience delusions or psychosis with religious content. The phenomenon affects muslims, christians, and jews alike, and can take many different forms. Some believe themselves to be prophets, others acquire an obsessive need to be clean and pure, others are convinced that the second coming is upon them. Something about being around so much intense spiritual energy, perhaps, drives otherwise sane people over the edge. Interestingly, there are a few places in the world that can have this effect on people - there is also a "Paris Syndrome", for example, and "Stendhal syndrome" affects some tourists in Florence.

So one reason Jerusalem might be the nucleus of so much tension and violence is because people have insanely strong religious convictions associated with it, and it even has the power to overcome rational thought in many. Another factor, in my opinion, might have to do with the heat. Almost every day I was in Jerusalem it was more than 100 degrees F - and the heat seems to bounce around on all that white stone and slap you directly in the face. Why do we always underestimate the effects of the weather? I know I've talked about the effects of too little sun here before, but it turns out that too much heat can affect us as well. Specifically, it makes people more aggressive. The effect is general (undergraduate test subjects are more likely to apply an electric shock, and express more hostile emotions, when it's hot), and also can be seen in specific scenarios. Drivers are more hostile and honk more in hot weather. Major league baseball pitchers are more likely to hit batters on hot days. Some psychologists are even fretting about the possible effects of global warming on this front - how are we all to get along on this small, hot planet?

To summarize: Jerusalem is jostling with the pious, the fanatical, the delusional, of at least three major (and somewhat contradictory) religious groups. Mix these folks together in tight spaces, add extreme temperatures, and watch as the city explodes.

Parents vs. kids?

2010-04-29T08:58:00.000-07:00

For some reason, I’ve been finding myself reading a lot lately about parent-offspring conflicts. No, that doesn’t mean conflicts with parenting rebellious teenagers or dealing with two-year-old tantrums – in evolutionary biology, “conflict” suggests something far darker and more sinister – a struggle that can often be a matter of life or death. In the world according to evolutionary biology, no relationship is totally harmonious. Everyone’s out for his or herself – or, more accurately, his or her genes. In terms of evolution, the more copies of your genes propagated into the future, the better.

Given that framework, one would initially think that parents and offspring should be on the same team – they share genes after all, and a baby animal (including humans) can be thought of as a tiny package of the parents’ genes – 1 unit of “reproductive success”. By having more babies, a parent theoretically increases his or her reproductive success – as long as those babies survive themselves. So shouldn’t a parent be interested in the survival of their own offspring? And since the genes in babies’ bodies would also be in the bodies of any siblings they should have by the same parents (that’s what it means to be related!), the babies should be rooting for the survival of their parents, too. If Mom and Dad stick around another season and reproduce, that means brothers and sisters, which means more copies of your genes around – again, increasing your fitness (indirect fitness, in this case). And that’s disregarding the obvious reasons you’d want parents to survive – to provide things like food and protection. So aren’t babies’ and parents’ interests perfectly aligned?

The answer is, sometimes, but not always. There are lots of examples where parents’ and children’s goals may be mismatched.

Sometimes, the conflict may occur before the child is even born – while still in the womb. If you think about it, it’s in the mothers’ best interest to give her baby just enough nutrition to survive and be healthy; that way, Mom doesn’t have to sacrifice her own health too much. On the other hand, it’s in the fetus’s best interest to steal as much as possible from the mother. That way, it can perhaps grow faster, be healthier, and be more ready to thrive after it’s born. This relationship is really very much like the situation for a parasite – how to take as much as possible from the host, ideally without killing her? In the search for nutrients, the fetus actually shoots “tendrils” out into the Mom’s bloodstream, searching for nutrients there. Some mothers’ bodies rebel at this invasion, causing a disorder called “preeclampsia” – which often results in a miscarriage. On the other hand, if the mother allows this fetal invasion, then it turns out that some of flow of bodily fluids goes both ways. The mother ends up with some cells from her baby – especially immune cells – floating around in her body, sometimes remaining many decades after she’s given birth! Like a parasite, the baby has left it’s mark in the mother’s body, and some of its cells will live and reproduce there for the rest of her life.

While the situation for us placental mammals is parasitic, in egg laying animals, offspring are much more vulnerable. In these cases, the parents’ interests often win out. A couple of recent studies have illustrated this point well: one in pipefish and one in stickleback fish. In both of these animals, dads are the primary caregivers.

Pipefish dads, in particular, are famous in the animal kingdom as the best dads around: these guys actually get pregnant. (Pipefish are closely related to seahorses, another group where males get pregnant; a pipefish basically looks like a seahorse that's been "straightened out"). The female pipefish lays her eggs directly into a pouch on the males’ abdomen, and the eggs proceed to develop and hatch inside Daddy’s body. Eventually, the pouch opens up, and out pop a bunch of bright-eyed little bundles of pipefish joy. However, some studies suggest that not all pipefish deserve Dad-of-the-year awards; in some cases, dads may selectively re-absorb the eggs in his pouch, effectively eating his babies. A study in a recent issue of Nature suggests that Dad may be choosing to snack on the babies when he thinks Mom wasn’t much of a catch – that is, if the eggs were from a smaller, less desireable female. There are some serious issues with that study, and they jump to conclusions, in my opinion, but still, it’s an interesting idea.

The stickleback study, in Proceedings of the Royal Society of Biological Sciences, has a similar theme: Dad eats babies. For the most part, stickleback dads are also pretty fantastic fathers: they protect their eggs (though they don’t get pregnant), clean them, fan them to make sure they get enough oxygen. Very committed. However, sometimes, stickleback Dads have been seen to nosh on those precious eggs, just like the pipefish. Here it’s not the quality of the Mom that’s important – it’s the likelihood that Dad is the real father that determines his behavior. Like many fish, stickleback males come in several “flavors”, each with a different mating strategy. The Good Dads are also the Traditional Male maters – they are big and strong, fight other males to win a good territory, then attract females by dancing and showing off the great nest site they’ve established. Other males, though, are much sneakier. These guys are much smaller than the Traditional Males, and they're able to dart into the nest and fertilize some of the eggs in the males’ brood on the sly. However, despite this sneaky strategy, it seems Traditional Male fish are on to these guys: it turns out they’re more likely to eat their eggs when some of them have been fertilized by a sneaker male. In both of these cases, it’s in the eggs’ best interests to survive and be cared for, but that’s not a good deal for the Dad. For Mr. Pipefish, it wasn’t worth putting the energy into being pregnant if he didn’t think he was going to give birth to high quality babies; if Mom wasn’t that great, these babies might not be that great, so why not save your energy until a better quality female comes along? For Mr. Stickleback, the strategy has to do with paternity certainty; he can’t be sure that those babies are really his, and it’s a total waste of energy to take care of someone else’s eggs – why risk it?

This last idea – if you’re not the real dad, then why invest in an offspring? – has some really interesting effects in humans, as well as other primates. I think I’m going to cut it off here, but next time I’ll hopefully get into how some of this plays out after birth!

The world through science

2010-04-15T09:33:00.000-07:00

Every once in a while, it's wise to try and evaluate the way you see the world. Why do you believe what you believe? Does it offer you the fullest, most rewarding experience of life? Perhaps those questions are impossible to answer - you can only experience your own experience, so how do you know for sure what another world view would feel like? But I like to think that at least the act of consideration is valuable (though most of the time, thought alone is not enough..)

So, with this preamble: I've lately been thinking about the role of science in shaping how we see the world. Lord knows it's hugely powerful - and I buy into most of it, as this blog clearly shows. But does this offer us the most rewarding experience? Is the world, through the filter of science, as beautiful and magical and infinite and sacred as the world through another filter - religion, or myth? I say yes, but I'm not sure that's true for everyone - and this is where the failing of science becomes clear. To many people, science can feel elitist, impersonal: laws and theorems handed down from on high, a covey of men in white lab coats decreeing that "This and this is true," that you are made up of cells and glued to earth by gravity. Most people, I've been realizing, meekly take in these declarations and ask no questions. Maybe they're taught these things in science class in high school, or read short summaries in the news, or hear snatches of the new scientific announcements from acquaintances. They take them in, nod their heads, and then run - towards something more creative, less frightening. Science presents itself to them as a methodical, chipping away at truth, and many of these are people who want to create, to imagine, and to dream. To them, science may feel like an oppositional force.

I've never actually experienced the world through religion or myth - the closest I can imagine would be the feeling of being a child again. Magic seemed possible, the lines of what defined reality were vague and blurry. When I was a child, my friend presented me with two eggs she had "found" in the woods - Unicorn eggs, I was informed. No matter that they looked suspiciously like the eggs found in my own refrigerator - I was immediately convinced they were from a magical being, and the two of us proceeded to spend several days tending the eggs, building a nest, crooning them lullabies. When my friend revealed the deception, I was utterly, completely surprised and crushed - I had fully believed I was about to hatch myself a baby unicorn. So that's what I imagine living in a world free of science might feel like - full of possibility.

At the same time, I've always been intrigued by science - my curiosity inevitably leads me towards explanations, and that's just where they are. There's something satisfying about a scientific explanation - it's tangible, almost, built on small, careful, measurable observations. It feels strong, real. It snaps into place, like a puzzle piece. This kind of knowledge is also very powerful - the ability to make generalizations, to understand one aspect of the world by thinking about what you already know is actually empowering. But the problem is, most people are not trained or empowered to use what they learn in one arena and transfer it to another. They are told that "discoveries" are made by someone else - those white-lab-coat men - and they are divorced from the process of discovery.

Because this is the actual secret of science - our puzzle-piece world view is full of gaping holes. We have many more questions than answers, and even if all 7 billion of us turned our attention to filling them, it's not certain that we'd ever be able to understand all of the mysteries of the universe. Trying to wrap your head around the vastness of the universe, the processes of randomness and order that created us in the first place, the complete mystery of consciousness which allows me to write this in the first place and you to maybe read and process it and respond - all of those are fundamentally mysterious, and I doubt humans will ever fully understand them. And it seems to me that science is the only world view that embraces the vastness of these mysteries - most religions try to fill up the gaps with stories, but when scientists make stories, we're forced to admit that they might not be true.

Part of the problem is, that last part sometimes falls away in the retelling. The media doesn't usually stress the "might not be true part", and neither do the science classes. We are told, "This is what we have discovered - because of the power of science, you must accept it. Now get on with your day." This is a huge problem - especially in the last century or two, the misapplication of science has gotten totally out of hand. Science is presented as omnipotent, omniscient, and so when it reveals a new "fact", that "fact" is sometimes accepted as the total, complete truth. When this happens, it almost always turns out to be a mistake. I think, for example, of scientists discovering the ingredients of mother's milk and creating baby formulas. Many of the formulas created over the past century have ended up being very harmful to infants, as the creators had only identified the major compounds in the milk, not the many micro-nutrients and immune cells and other important stuff that mothers are designed to feed their babies. Even today, breast-feeding has been shown to have many, many benefits over using formula - but many women still choose to put their faith in science.

This may sound like I'm contradicting myself - science is good, science is bad - but the thing is, it's not that type of issue. Science is a tool - a way of looking at the world and building off the ideas of others and slowly, intricately building ideas and explanations. Science is a way of generating explanations, not answers - the rules of the game state that any of these explanations must be thrust aside if we ever think up something better. This has happened a lot in the past, with humors giving way to neuroses giving way to neurotransmitters and hormones, and so we do well to be skeptical of science's "answers" - they are almost never the whole picture. But to me, this method is exciting and useful because it allows any of us to take the tools - the method of questioning and observing - and the explanations that seem to hold up pretty well, and try them out for ourselves. If we turn those tools to understanding the world - and remember to do so with a sense of humility, knowing that many things are and will remain mysterious - I think that the picture that emerges is more surprising and exciting and, again, empowering, than the view from any religion. We can be involved with uncovering our worlds.

Important primate research

2010-04-02T17:06:00.000-07:00

Scientists Successfully Teach Gorilla It Will Die Someday

Thanks, Darby, for sending me this video from The Onion. I hope someday I can replicate this study with macaques :)

Hello Kitty, babies, and social bonds

2010-04-02T16:53:00.000-07:00

Living in a group can be pretty stressful. We humans are certainly aware of this - we have to deal with social stresses like competition for sexual partners, humiliation from social encounters, anxiety over what others think of us, etc. But unlike some species, like chimpanzees or baboons, we don't usually have to worry about having our food taken from us or getting beat up. While sociality always comes with psychological stresses (for other primates, as well), it can also come with physical stresses. In fact, I described in a recent post how fear alone might create a complex social system.

Given that sociality is so stressful, why live in a group at all? This issue is hotly debated by primatologists, with explanations usually citing foraging efficiency (i.e., it's easier to get food) or predation avoidance (i.e., it's easier to avoid getting eaten). But the answer still isn't clear. In the long, long run - over evolutionary time - we're not sure what factors selected for primates living together, or how this change happened. What we do know is that many primate societies use certain behaviors as "glue" to help keep the group together once it's formed. If living in a group resulted in constant stress, it wouldn't be very sustainable - thus, primates have developed a few behaviors that can reduce stress and promote group cohesion.

I've mentioned one of these behaviors here before: grooming. Grooming apparently can help prevent conflict, lower stress, and form alliances; grooming is so important that it can even be traded for other goods and services (like food or sex). Another behavior that is found in many primate groups and reduces stress is infant handling. When a new baby appears in a group, other group members will show intense interest in the baby, and want to hold it. In most primates the behavior is particularly pronounced in females, and males show it to a lesser degree. Sound familiar? Turns out humans are primates, too, and we show this same behavior.

I've often found myself waving and smiling at strangers' babies, but I never consciously thought that I was using the baby as a social tool. I just thought the baby was cute, and was following my instinct to approach it. However, it turns out that my response to a baby's "cuteness" is a deeply hard-wired instinct. Humans all over the world respond in the same way to any stimulus that has certain features: a big, round head with big, forward-facing eyes, a small nose, and a roly-poly body (with short, chubby arms and legs). These signals are such a strong stimulus for us that we respond the same way to the young of other animals (puppies and kittens, for example), and even to inanimate objects - "cute" cars, like a mini-cooper or a vw bug tap into this same response. Cartoonists and animators have even taken advantage of these impulses in creating characters that people are intensely drawn to - and making big bucks in the process. Take a look at Hello Kitty - she's got all the baby features that tap into our cute response, which explains her enormous, world-wide popularity. Why is this response so strong? Probably because we give birth to such helpless babies. For the human species to have survived this long, it's been adaptive for us to have a strong impulse to take care of our young.

The more I learn about other primates, the clearer it becomes to me that humans truly belong to this group - we're just another species of ape. Like macaques, who might pass around a new infant to promote social cohesion, we humans us babies to create peaceful social relations and strengthen social ties. Going back to my encounter with a strange baby on the street - while I've never asked to hold a stranger's baby, I usually end up smiling at the parent, creating a moment of connection with a stranger. And within a social network, babies are even more important: when a new baby is born, family and friends will usually travel to come visit it, strengthening social ties. Someone might even be declared a godparent, cementing their bond to the family unit.

And, stretching the concept, we can also think of cartoons and cute pop icons bringing people together. Maybe it's just because there's some kind of anime convention going on in Seattle right now, and the streets downtown are full of adults dressed up as "cute" anime characters. But to me, this seems like yet another example of how the power of baby-like signals can bring people together and unite people with a common interest. I bet none of those people realize that they're just submitting to some of their deepest primate instincts!

It's a small world after all?

2010-03-28T09:46:00.000-07:00

I've been reading a great book by Tom Standage called "An edible history of humanity". While the book touches on lots of interesting facets of human behavior surrounding food throughout history, I was especially interested in the first section, describing the change from hunter-gatherer systems to agriculture. As I pointed out in a recent post, this lifestyle switch actually had seriously negative consequences for our ancestors. Health worsened, lifespan decreased, and farmers were generally smaller, weaker, and less healthy than their hunter-gatherer ancestors. Standage presents this same data, but also describes another change brought about by agriculture: the switch from egalitarian social systems to a social system with a power hierarchy. Both archaeological evidence and observations from the few remaining hunter-gatherer tribes suggest that these groups tend to by almost militantly egalitarian (if you can roll with that oxymoron...), forcing group members to share all of their possessions and implementing social norms to prevent anyone from becoming too proud or pleased with himself. Standage describes tribes in which hunters are routinely ridiculed for the quality of the prey they've brought down ("It's nothing but skin and bones!"), or other groups where the hunter doesn't get credit for the kill at all, but rather, the maker of the arrow that shot the beast gets the praise. Both of these norms are meant to keep anyone in the group from gaining too much power or thinking themselves better than the others. The fact that such strategies have emerged implies that cooperation among the group is extremely important in these sorts of societies.

Contrast this with our modern way of thinking: we train children to think of themselves as individuals, and work on polishing their self esteem so they believe they are unique and specially skilled. Indeed, the American dream - the core goal in our society - rests on the individual rising above others in the group, amassing a huge store of personal wealth. In a traditional hunter-gatherer society, there can be no wealth: as mentioned, all possessions are shared. However, as Standage points out, with the advent of agriculture, humans for the first time had a surplus of preservable foods like grains. Never mind that these new foods were not as nutritionally beneficial as the more varied diets of the hunter-gatherers (which is probably what led to the stunting and poor health of the new farmers) - the important thing was that these foods could be stored for long periods of time. Suddenly, some farmers were "wealthier" than others, depending on their food stores. From this differential distribution of wealth, Standage explains, some individuals began to trade and offer favors, giving them power within the community. This power structure would then spread from the community over a greater area, resulting in the complicated structures of empires and kingdoms.

These ideas have been churning in my mind for the last few weeks - how agriculture is so inextricably linked to individualism, how an individual could rise to power by being particularly generous. So I immediately connected these ideas to a recent New york Times article on cross-cultural attitudes towards generosity and fairness. In the experiment, researchers visited various groups around the world - including a group of Hadza hunter-gatherers on the Serengeti, an indigenous Amazonian tribe, Siberian reindeer-herdsmen, Buddhist monks, and group of Midwesterners. With each of these groups, the researchers performed the same experiment, a game called Dictator. In the game, one participant had the chance to share a valuable prize with an unseen partner. Both the dictator and partner were anonymous, so there was little social pressure to share, and no negative consequences for not sharing. In essence, the dictator could choose whether or not to give money to a stranger, with the condition of complete anonymity. Since the identities of the players were never revealed, the "best" strategy is obviously to keep all the money for yourself - why share with a nameless, anonymous stranger?

However, the researchers found that in many groups, the players shared a large proportion of the money with the other player. What's more, the group that shared the most, giving about 45% of their money was the Americans (Missourians, to be exact). Apparently, more "Westernized" groups - those that lived in agricultural societies, for example, and those that belonged to an Abrahamic religion - were more generous with strangers. And, when in a variation of the game that allowed the partner to "punish" the dictator for their decisions in a past round, this same group was more likely to punish than to forgive. Indeed, even when the punishment cost them part of their reward, members of these groups were more likely to make the sacrifice, just to get back at their "unfair" partner. On the other hand, hunter-gatherer groups were less generous with strangers, giving only about 25% of the reward, but were also less likely to bear a grudge or punish their partner.

What's behind this pattern? Does this relate to farming vs. hunter-gatherer lifestyles? The population size in these various groups (and the degree of relatedness in those groups)? Something about the religious tenets of the various groups? Or all of the above?

As you can probably guess, I'm going with the latter (and perhaps there are more explanations, as well!) The Times article discusses some of these explanations, so I'll only do so briefly - but to me, the answer seems to rest on the prevalence of strangers in each of these societies. In small groups, like hunter-gatherer tribes, every group member certainly knows every other group member. In fact, most group members are probably related, so people are doubly inclined to share (not only are the other members acquaintances, they're blood relatives. A classic case of kin selection!) On the other hand, agriculture leads to larger communities, where the members are less likely to know each other well, if at all. The Missouri community would be the extreme of that spectrum in this experiment - while the researchers chose a small town, even in a group of about 2000, not every member will know everyone else. As a result, in these larger groups, members have no immediate drive to be fair or generous with each other. This is a problem - how can you get people to belong to such a large group and not mistreat each other? According to this experiment, the answer is to codify cooperation into the culture. This codification is a prominent part of Judeo-Christian religions, and is also taught to children in these groups from infancy ("Do unto others..."). In order for these large societies to function, everyone needs to follow the Golden Rule.

I'm still trying to figure out how these two visions fit together: hunter-gatherer tribes as more egalitarian, more likely to share and treat everyone equally, but less likely to worry about fairness or generosity when sharing with a stranger. Both make sense when argued alone, but together, I'm not sure they form a cohesive picture of what's going on here. So I'm still feeling fairly skeptical about the results of that "fairness" study. In particular, I wonder if the findings might have to do with cultural attitudes about research in general. Perhaps in societies where people are more familiar with the concept of research, people are aware that they are being measured somehow, and are more worried about the scientist's judgments (or about somehow being recorded in the study as being "stingy"). Basically, it's not clear that these cross-cultural comparisons are valid, because some groups might change their behavior when they're being observed, while others might not. It's the classic quantum physics dilemma - by observing the system, you're actually changing it!

I'd love to hear any of your thoughts on this. As you can see, I'm still trying to work it out for myself...

Three simple rules for sociality:

2010-03-13T07:26:00.000-08:00

Three rules for sociality: 1. Stick together; 2. Don't attack anyone who you can't beat in a fight; and 3. If you're feeling worried about getting attacked, groom someone.

These three rules, along with a couple other parameters, turn out to be pretty much enough to explain all of the complexity and diversity of (non-human) primate social behavior. A description of the paper was published in PLoS Computational Biology a few months ago (which means you can read it for free!) Basically, the researchers created a computer simulation where players inhabited a "world" (called GrooFiWorld, for groom, fight world) filled with other players, whom they had the opportunity to interact with. On each "turn", players would move throughout the world, interacting with other individuals who came into their personal space. The three rules above governed most of their behavior: if they ran into an opponent they could likely beat in a fight (based on the individuals' assigned dominance scores), they would attack. If their "anxiety" score was high, and they didn't think they could beat their opponent, they would groom them instead.

By tweaking parameters (average distance between players, intensity of attack), the researchers found that the model produced pictures of very different societies. Interestingly, these societies showed a lot of the same features of primate societies in real life. In particular, they mapped on to the diversity of social behaviors seen in macaques (which are often characterized as having a spectrum of society structures, from "despotic" to "egalitarian"). For example, in different models, the amount of aggression and the amount of grooming varied (with numbers closely matching what's seen in various macaque societies in real life); in some models, low ranking individuals were more likely to groom higher ranking players; the social structure - i.e., where every player was standing, depending on rank - was similar in some models to what's seen in real life despotic societies; and some runs produced reciprocal grooming ("I scratch your back, you scratch mine"). Also important: the traits that "go" with despotic societies all turned up in the same model, while the egalitarian traits more or less showed up together, as well.

Who cares? I thought this model was exciting because it demonstrates that something we usually think of as very complex and driven by sophisticated thought (social behavior) could just as easily be accomplished by robots following simple rules. Just because the end pattern looks complicated doesn't mean that it can't emerge from simple interactions. Now, I don't think this disproves that monkeys are extremely intelligent (we've got more than enough evidence for that), but it does suggest that some of the underlying, basic mechanisms driving their behavior might be very simple. The same goes for humans, in fact: maybe someday soon, researchers will be able to explain the diversity of human interactions with a few simple rules.

The eyes have it

2010-02-27T12:40:00.000-08:00

I love it when I stumble upon an article that reveals a whole field of research that I've never heard of. In this case, I found an article that revealed that for decades researchers have been looking at the connection between eye color and personality. While most of us take the saying "the eyes are the windows to the soul" metaphorically, apparently some psychologists believe the connection is completely literal. One researcher wrote a whole book on the subject, in which he apparently claims that light-eyed athletes are better at self-paced tasks, while dark-eyed athletes have faster reflexes. He compares this to hunting strategies in animals - where apparently, light eyed animals are sit-and-wait predators, while dark-eyed predators tend to use quick reflexes to catch their prey. Granted, I haven't read the book, and maybe the argument makes more sense when it's explained in detail - but from the synopsis, it sounds outright stupid. However, according to the paper that caught my eye in the first place, this book, by Morgan Worthy, is considered "influential" in the small, strange world of eye color psychologists.

From what I can gather, the reason that anyone is studying this in the first place is because they assume that eye-color is a sexually selected trait. Like feather color in birds or fin color in fish, they argue, different eye colors exist because they tell us something important about the potential mate-quality of their bearers. Unlike in most animal cases of sexual selection, however, this process is purported to have been driven by males choosing females for the trait (eye color) that they think will make them a better mate - either because they have better genes, or can better provide for their young, etc.

Now, I have a major problem with this underlying premise. If eye-color were a sexually selected trait, in the manner of bird feathers, human males should show a strong preference for one eye color over another. Women with blue eyes, for example, would be expected to be universally preferred, while brown-eyed girls would be considered less attractive. While some individual men show these kinds of preferences (in both directions, btw - some prefer brown, some blue, etc.), in my non-scientific survey of friends and acquaintances, I've never noticed any strong pattern in either direction. I've never seen any sign that eye color is nearly as important a factor in determining attractiveness as, say, face shape, or body proportions. Even the eye shape seems more important to me than the color.

Beyond the dubiousness of the sexual selection argument, I won't even get into some of the proposed relationships: the whole deal with hunting and athletic style is, as I said, ridiculous. And other supposed connections - that light eyed people are more prone to alcohol use than dark-eyed people, for example - seem spurious at best. There are probably other differences - either physiological or cultural - that better explain these findings. Eye color just happens to correlate with some of these differences. For example, Nordic people have high rates of depression (probably because of low levels of sunlight during the winter). These people are also likely to have light eyes, because that is a common genetic trait in those areas. So, does light eye color cause winter depression? Of course not! This is just another example of the difference between correlation and causation.

OK, so with that disclaimer (the whole theory behind this paper seems flawed to me), I'll swallow my disbelief and explain what these people found. They claim that sex-ratios were especially skewed in northern Europe during the last Ice Age - basically, there was a shortage of men. Because of this uneven situation, men could afford to be very picky about who they mated with. And, according to these authors, they chose more often to mate with light-eyed females because ... light-eyed females are less agreeable! Yes, males chose to mate with the most disagreeable females around, because, as the authors explain, this trait (while presumably unpleasant for the male in question) was related to the female being more competitive. And of course, females that are more competitive are more likely to better provide for their children, because they are so cut-throat in gathering resources, are unlikely to share with other women, etc. So, the infallible logic chain goes: being disagreeable (as measured by personality indices) = being more competitive = being a better mother. And all of this, apparently, is picked up by men by looking at eye color. Not by, say, assessing body fat (which would be a good indicator of how good you are at actually getting your hands on resources) or watching how the woman interacts with others. No, eye color is the best indicator here.

Anyway, the study did find a connection between eye color and Agreeableness score for Northern Europeans (but not for Southern Europeans). For any statistic nerds out there, they found this effect by dichotomizing the continuous variable (Agreeableness score) - a huge no-no. And even then, the effect looks small (although they give no error bars).

I feel a little guilty for picking on this study, as it seems like such an easy target. But maybe I just don't understand the field well enough, having read only one paper. However, for the time being, I'm going to stick with the other evolutionary explanation I've heard: that eye color pigmentation co-evolved with skin pigmentation, and is an adaptation to different climates with different light levels. However, I guess there is something to the argument that there's something weird about Europeans. Why all the color possibilities in Europe, when most of the rest of the world has brown eyes?

Rethinking farming

2010-02-22T17:05:00.000-08:00

When proponents of the local/organic/slow food movements speak of "returning to our roots" or "eating a more natural diet", they usually mean eating foods grown on small, local farms (or growing it yourself). However, some would argue that there's nothing "natural" about any type of agriculturally based diet. In fact, evidence suggests that the transition from being hunter-gatherers to farmers actually made us sicker and frailer. The advent of farming began in the Middle East around 10,000 BC, and is commonly referred to as the "neolithic revolution", because of the change it made in the human diet and lifestyle. People went from living in small, nomadic tribes to much larger, sedentary groups. This was also a turning point in our relationship with the natural world, one might argue, as humans began to modify and control their environments to a greater extent.

This sudden shift in lifestyle spread rapidly from the Middle East throughout Europe, and populations exploded (some estimate 100 fold!) along the way. I had always assumed that agriculture spread (and populations grew) during this period because agriculture was simply more efficient - people produced more food, and thus lived longer/could spend more time having babies. But it turns out, I got this relationship backwards: the introduction of agriculture actually drastically deteriorated our ancestors' health.

How can anthropologists tell what health conditions were like more than 10,000 years ago? By being very, very clever. Scientists can look at clues in ancient bones to identify diseases related to malnutrition that might have plagued Neolithic people. For example, tiny lumps around the eye-sockets (in the periocular membrane) are signs of disease, while tiny holes in another eye bone (the cribra orbitalia) are caused by anemia - Like this:

Other clues include lines in the bones or ridges on the teeth (called Harris lines) that show evidence of periods of malnutrition. These look like this:

Basically, what researchers have found consistently is that pre-Neolithic Revolution hunter-gatherers show less disease, less anemia, and less malnutrition than the post-Revolution agriculturists. These findings can also be seen in other groups around the world pre- and post- agriculture - for example, in Native American tribes, farming seems to have been equally as detrimental. Agriculture also drastically decreased life-expectancy and made us smaller and weaker; at a talk I attended recently, the speaker suggested that humans are only today returning to the robustness (the average heights) associated with our pre-farming ancestors. So overall, the beginning of farming made us weaker, sicker, and with a less stable food supply. That's on top of the environmental damage it caused down the road.

The negative effects of farming are probably due to several factors: farming might have created a less nutritious, less varied diet (think of the rice and beans of many peasant farmers around the world), and living in close proximity in large groups certainly led to the spread of diseases. There's not much we can do about it now - all 6 billion of us certainly can't survive by hunting and gathering alone. But it is interesting to challenge some of our assumptions about what we think is the "best" or "healthiest" way to live - or what how humans were "meant" to behave. This is just another example, among many, of how the way we live today is vastly out of sync with what we evolved to do. And, as in this case, what we are "meant" to do - how we evolved - is often no longer an option, because our current environments are so different from those of our ancestors. Still, learning all this made me think that maybe there's some truth to the "Caveman Diet" that's been catching on lately (The New York Times wrote an article about it last month). Maybe I should put down the bread and try hunting some of the neighborhood wildlife - roasted raccoon, anyone?

Monkeying around: social systems and temperament

2010-02-17T23:07:00.000-08:00

Sorry I've been gone for a while - I've been pretty busy lately. Among other things, I've been working on writing up some of my own research for publication, which can be all-consuming. For weeks, I felt like I did nothing but make graphs and read papers about monkeys... although I guess that's generally what I do, so maybe it's just been more intense than usual! In the interim, I've come up with a dozen ideas for topics I want to talk about here - I only hope I have time for half of them. Unfortunately, at the end of a long day of being a grad student, I don't always have the energy to write down my ideas here, so many of my ideas languish forever in half-written posts. Such is the fate of the non-professional blogger, I suppose - I'm hardly alone. Anyway, as I approach the one year anniversary of this blog later this spring, I'll work harder on ramping up the frequency of my posting. Until then, thanks for your patience, everyone!

While it's fresh in my mind, I thought I'd just fill you guys in on some of the ideas I've been working on lately. Basically, my research for the last year or so has dealt with temperament in monkeys - what is it, how can you quantify it, how stable is it? How early in development does it appear, and how much does it change as you get older or find yourself in different situations? All of these are pretty broad questions, but for this last paper, I actually found myself tackling an even broader one: how does temperament - your own, personal behavioral patterns - relate to your social interactions - how you behave with others?

For this project, I was studying data on temperament in three closely related species of macaques: longtail, pigtail, and rhesus macaques. While these monkeys are pretty close relatives (especially longtails and rhesus - pigtails are a more distant cousin), they have some major differences in how they structure their social systems. Rhesus macaques are what I've referred to here as "despotic" - they've got a very rigid, linear dominance hierarchy, where everyone knows his or her place in the pecking order. Pigtails and longtails, on the other hand, are a little more laid back: they attack each other less, groom each other more. Basically, what I was trying to discover is whether there are some underlying differences in temperament among these species that I could use to explain their different social systems.

Now, before I talk about my results, I'm just going to build the suspense a little by explaining why this is a cool question (well, why I think it's a cool question). While we might think of behavior as something species-specific, and we might think of social systems as being unique to a species, we rarely bridge the gap. When we do, I think there's a tendency to think of social systems creating certain personalities among individuals. For example, if you were a monkey researcher, you might suspect that being in a despotic, very aggressive society would make rhesus monkeys more aggressive than monkeys who were not around so much violence (like, say, pigtails). This is the argument that's often used in humans, right? We say that because someone is exposed to a lot of violence and aggression, they become aggressive themselves.

But what if you flip that relationship on its head? Instead of saying the rhesus are aggressive because they're around other aggressive monkeys, you could say, "Rhesus have an aggressive society because on, average, individuals are aggressive." The idea here is that there's some biological tendency towards a certain temperament in the species, and it's having that temperament that shapes the society. Not hard to imagine, perhaps, but an intriguing thought, nonetheless. How do you separate these effects to figure out what's really going on? Luckily for me, I had data on temperament in monkeys who were being housed in single cages - not part of any social system at all. So all I had to do was use these behavioral observations to identify temperament traits, find scores for all the monkeys in my sample on these traits (btw, I had more than 900 monkeys in my sample. Many of them were observed multiple times.), and then do some cross-species comparisons.

What I found supports that weird, backwards hypothesis: monkeys do indeed differ by species in their temperament, and those species differences are, for the most part, related to the way that species behaves socially. So rhesus turned out to be both more aggressive and more fearful - indicating that if you're a rhesus, it's good to have a default strategy for how to behave in a conflict (if you back down fast, you probably won't get hurt). I also found some other cool stuff - the species differences appear to be more pronounced in males, for example, probably because males are the ones who really have to compete in dominance interactions to earn their rank (in macaques, female rank is at least partially inherited. You're born with your mom's rank, more or less, and the littlest sister eventually outranks her older sisters).

I'm still working on some edits for the paper, and trying to figure out a better way to run one analysis (the way that will give me the prettiest graph!). But I'm excited to start getting some feedback on it - and eventually, to discuss with some other scientists how it fits into our larger understanding of how our own, inherent temperaments are related to our social interactions. It's not clear whether this type of work applies to humans - obviously we can't do cross species comparisons, though it would be interesting to try some cross-cultural comparisons and see if there are some personality differences that persist even when culture is taken out of the picture.

While I don't know if this applies to humans, I do know that it fits in nicely with some of the other monkey data. One cool study by John Capitanio down at UC Davis found that the mixes of personalities within small, newly formed groups of monkeys determined the social atmosphere of the group. Like a chemistry experiment, mixing certain personalities resulted in a particularly nasty, fight-prone group, while another mix created calmer, friendlier groups. The bottom line: be aware of your own personality, and watch out who you spend your time with. The wrong mix could just end in antagonism.

Using monkeys as models

2010-02-03T22:44:00.000-08:00

I read an article today by several researchers, including Sarah Brosnan (the scientist who studies monkeys' senses of fairness and justice, who I've mentioned here before), that really nicely highlights why it's important to study non-human primate behavior. When people here "animal studies", they immediately think of medical experiments, which often prompts a strong reaction of some kind. However, studying animals is not just a semi-ethical way of figuring out how our inner organs function (that is, a way to find out without cutting up a fellow human) - they're also vitally important to understanding our behaviors, how our brains function, and the evolutionary mechanisms that make us act the way we do. This is why I study monkeys, and anyone who's read this blog will be familiar with some of the parallels I see between human and animal behavior. However, just in case you wanted a fuller explanation of the importance of animal studies, give this Brosnan et.al. paper a look. (Here's the official link to the paper, but you can only access the abstract for free at this site). The paper was intended for an audience of human psychologists, so it very clearly lays out exactly what we can learn about human social interactions and personality by studying other animals, especially other primates.

I liked how the paper laid out several examples of how primate and human studies could be complementary. For the first example, the authors describe how personality studies in humans have informed and shaped the study of temperament/personality in animals. As this is something that I am currently working on, I'm actually a little skeptical about the way that the paper outlines this relationship: in my opinion, animal studies haven't taken enough from the human research on this point. Animal studies of temperament are mostly focused on identifying traits, and especially on showing that those traits correspond to what's called "The Big Five" Personality traits in humans: conscientiousness, openness, extroversion, agreeableness, and neuroticism. While these studies have proved that these traits are present in many types of animals, from octopuses to chimpanzees, they haven't followed the lead of more sophisticated human models that illustrate personality as something context dependent. Yuichi Shoda, Walter Mischel, and others have demonstrated that in humans, personality isn't some solid construct, but something that varies depending on the situation. For example, a shy person isn't necessarily always shy, but perhaps is in specific situations (e.g., when meeting new people, when speaking to groups of people, at cocktail parties, etc.) This more subtle view of personality hasn't caught on in the animal literature yet... but at least there's some dialogue going on between the two fields.

The Brosnan paper also mentions some other areas of research that are closely paralleled between the two fields (human and animal psychology). Brosnan mentions her own field, equity and fairness research, and describes how many of her own experiments were directly adapted from economics research with human subjects. The paper also describes the impact of primate behavior studies on explaining inter-group violence humans. According to the article, no one had really noticed that most inter-group violence (i.e., war - between countries, gangs - groups, really) was conducted by men until someone made the point that in the few instances where it has been observed in other primates (most notably in chimpanzees), it was an all-male affair. This observation has prompted what's known as the "male warrior hypothesis" - that men identify with groups more strongly with women, and are quicker to feel a threat to their group. This hypothesis makes so much sense to me; for example, it explains why more men than women get so worked up about sports - they are identifying with their team as their "group".

Combining two of these ideas - how studying primates can help us learn about our own desires for fairness and our aggressive drives - I wonder to what extent non-human primates seek revenge? I've mentioned here that primates will punish a peer who they feel is cheating them, but I wonder if there are any circumstances in which an animal will seek retribution, violently, from someone who they feel has wronged them. Most violent interactions within primate societies have to do with dominance - who has access to resources like food and females. In many primate societies, dominance hierarchies are pretty inflexible, and lower ranking individuals won't try to punish a dominant animal for being a jerk - so if the alpha male beats you up, you take it (or take out your rage on the guy below you in the pecking order). Of course, primate societies vary in how "despotic" or "egalitarian" they are, and in some species, it's more common for the subordinate animal to fight back. And, as I've also mentioned here, primates are certainly capable of complicated social climbing and Machiavellian plotting. But I wonder if there's any way to prove that monkeys will direct violence at someone else with the explicit goal of revenge - rather than just trying to improve their own position in the dominance hierarchy. Could a monkey, like a human, try to get back at someone for doing them wrong? If so, it would tell us a lot about our own human flaw of vengefulness. I'll let you know when I figure out how to do that experiment, and Nature publishes my paper...

"The Great Leap Forward"

2010-01-29T10:46:00.000-08:00

Yesterday I attended a lecture by Mark Thomas, a geneticist and anthropologist at University College London, in which he offered some pretty fancy models and genetics-based arguments to explain the mysterious explosion of human technologies that occurred about 40 thousand years ago around the world. Around this time, early Homo sapiens (and possibly Neanderthals) abruptly became far more sophisticated, creating complex weapons like throwing spears and bows and arrows, fish hooks and traps, and grinding tools like mortars and pestles. At the same time, cave paintings, body ornamentations, and musical instruments all appeared. The sudden onslaught of so many innovations at once has puzzled anthropologists for years. Scientists refer to this unexplained phenomenon as "The Great Leap Forward" or the "Upper Paleolithic Revolution" - names which, to my mind, seem oddly reminiscent of the communist revolution in China.

But whatever you choose to call it, it's clear that this was indeed a revolution or renaissance. Consider for a moment the technology that existed before this period: for a million years, humans had been using pretty much the same old simple, stone hand axes. These were a huge step up, of course, from the most popular tool of the previous million years: Olduwan stone choppers, which were just roughly shaped rocks. So after millions of years with little change, the abrupt explosion of new technology is certainly puzzling. However, researchers have struggled to think up a good explanation for the change. Some have suggested that the innovations appeared as a solution to new environmental challenges as humans migrated to Europe and global temperatures cooled. Another idea is that the new technologies actually mark a change in human genetics - perhaps some shift in neural wiring. Unfortunately, neither of these explanations holds up well to scrutiny. The revolution occurred at about the same time in places around the world - from Australia to Western Europe - so it's unlikely that genetic changes could spread that rapidly. And some of these technologies briefly appeared in South Africa about 100 thousand years ago, then disappeared again - another mystery - which implies that they probably aren't related to climate change.

Thomas uses his background in genetics to offer a better explanation for the Great Leap Forward. By treating cultural evolution like biological evolution - comparing cultural behaviors like tool making to genes, that can be passed from generation to generation - Thomas was able to create a model to explain the flow of ideas during this time period. The model is quite complex, and takes into account factors like the amount of skill that the average student will acquire from a given teacher and the probability of a student choosing the best teacher in his social group to learn from. Basically, he created a simulation of the learning process among multiple migrating populations where individuals differ in their abilities. Then, he ran the model on a computer, altering factors like the population density, the number of social groups, and the amount of migration between groups. What he found was that these factors - density and migration - can create an increase in skill level within the groups. At the same time, if population falls below a certain threshold, technology will be lost. This "flip side" of the coin explains a strange note from the annals of anthropology: the loss of technology in Tasmania about 10,000 years ago. While Tasmania was once connected to Australia and shared all of the same technologies found in that continent, about 10,000 years ago, the land bridge between the two disappeared, and by the time the Europeans arrived, the Tasmanians no longer knew how to make items like fish hooks, barbed spears, boomerangs, or cold-weather clothes. According to Thomas's model, this was simply a result of a smaller population - with fewer people, according to Thomas, technology will necessarily be lost.

Thomas's population-technology link matches up nicely with some other studies, which indicate that population levels around the world were increasing during the Upper Paleolithic. Anthropologists once imagined that this population increase occurred because of the better technology, as new and better tools increased survival rates. However, Thomas's study turns that view on its head, showing that population growth alone can cause technological change.

This model is exciting because it challenges the way we usually think about innovation and technology: here, technology is not the result of bigger brains or shifts in the way we see the world, but simply a matter of getting enough people in the same place at the same time. To me, this seems to mirror the technological innovations of the last century, which have also coincided with enormous population growth. As Thomas put it, "Cultural sophistication reflects human interactions, not human intelligence." The implications of this are also enormous in how we think about the evolution of the human mind. If all humans needed to start creating new technologies was a bigger population, then that implies that we already had the ability to make those technologies before - our brains were already capable of complex thinking. Thomas pointed out that this means that, contrary to what some evolutionary psychologists have suggested, "clever brains didn't evolve to make clever things." So why did those clever brains evolve in the first place? We'll have to keep searching for an answer to that one...

Some reflections on Haiti

2010-01-23T15:54:00.000-08:00

I've been following the news of events in Haiti carefully since last week's earthquake. The staggering devastation caused by that single event really drove home our human helplessness before the power of nature. What's been interesting is that as I've learned more about Haiti's history by following the earthquake story, I've come to realize how the destructive conflict with nature in this area has really gone both ways. This is true all over the world, of course - we destroy our natural resources, then fret about the dangers of climate change and the like.

In following the story of the earthquake (including our response to it here in the West), I've learned far more about the history and politics of Haiti than I knew before. It's a terrible story in many ways - the underdog country that keeps getting viciously screwed over by countries like France and the U.S. (For a great rundown on some of those historical issues, see this summary by Bill Moyers. Jameson also has some great information on his blog). But even removing the layers of human conflict that have rocked Haiti over the years, there is still a tale of conflict at work here: conflict between people and nature. Although Haiti was originally settled by the French because of its seemingly boundless fertility (especially for sugarcane), today it is largely a dead island. While farmers struggle to coax crops out of the ground all over the island, in 1990 (20 years ago), researchers were already worried that less than 10% of the ground was really suitable for farming. At that point, soil was being eroded at a startling rate because of deforestation, leaving behind sand and rock, where nothing could take root. The situation has only worsened since then, while the demand for food has grown tremendously (the population of Haiti has been skyrocketing in the past decades, with an annual growth of about 1.75%. That may not sound like a lot, but consider: China has an annual growth of only 0.5%!) Due to unsustainable farming practices, the jungles of Haiti have been completely decimated. The difference between Haiti and the Dominican Republic (its neighboring country on the island of Hispaniola) is so stark that it can be seen in satellite photos: on one side, the island is green, on the other, a brown desert.

The results of this assault on nature has been terrible for the Haitian people: earthquake aside, nature has been punishing them for years with hunger and malnutrition. More than a million people have fled Haiti over the past decades as environmental refugees - trying to escape the destitution that accompanies their dead earth.

While it seems likely that poor conservation techniques date back to the French colonialists, why haven't farmers tried to improve their situation by adopting better farming practices? Studies suggest that a number of factors influence a farmer's decision to adopt sustainable soil practices, and that poverty may continue the cyclical process of destruction: farmers without education, those who produce less, and those who have been forced to turn elsewhere for additional income are all less likely to adopt soil conservation practices.

From an extreme viewpoint, then, the tragedy in Haiti could be seen as just a continuation of the environmental struggle that's been going on their for centuries - the struggle of a people who have forgotten how to honor and respect the earth. This is a struggle that's been playing out around the world, of course, and one that we desperately need to resolve. Hopefully we can take Haiti as a warning and begin to take note of the unsustainable and destructive practices in ours and other countries. And, if there is a silver lining to all this for the Haitians, it's that perhaps they will get world support in rebuilding their country with a healthier agriculture system - one that will reverse this trend of violence towards the earth, and benefit the people in the process.

Culture and the mind

2010-01-12T14:47:00.000-08:00

Last Sunday's New York Times Magazine had a great article that really got me thinking about how culture shapes the human mind. The article, called "The Americanization of Mental Illness", explains how the spread of American culture, through media and medicine, has totally altered the expression of mental illness around the world. The article describes how mental illness has taken different forms at different time periods (think of 19th century female "hysterics") and in different places, and gives a few illustrative examples:

"In some Southeast Asian cultures, men have been known to experience what is called amok, an episode of murderous rage followed by amnesia; men in the region also suffer from koro, which is characterized by the debilitating certainty that their genitals are retracting into their bodies. Across the fertile crescent of the Middle East there is zar, a condition related to spirit-possession beliefs that brings forth dissociative episodes of laughing, shouting and singing."

However, since Western psychology has gained a foothold in many of these countries, mental illness has rapidly homogenized, with patients the world over now drawing on the same symptoms to express their mental state. Depression in African villages is now expressed with the same symptoms as in Europe, and eating disorders like anorexia have become increasingly common in out-of-the-way places where they were unheard of before. While some have suggested that the increase in eating disorder is purely a result of body image distortion from Western fashion and TV images, this article suggests that the increase might be more driven by the specific symptoms entering into the cultural consciousness.

The existence of this globalization of mental illness doesn't mean that these illnesses are being "faked" in any way, or that the mentally ill are acting; rather, it's an illustration of how culturally sensitive the mind is. Within a culture, there are patterns of behavior that are associated with mental distress, perhaps taught implicitly, and people draw upon these behaviors when they are trying to express their distress. The article also mentions the shift in conceptualization of mental illness that comes with this "Americanization" of symptoms: in the West, we think of mental illness as a "sickness like any other", not the patient's fault, and not the result of evil spirits or the like. However, some new research shows that this way of thinking about mental illness might actually be more detrimental for the patient, as they are more likely to become defined by their disease, or treated as though they have a permanent condition.

I don't usually study culture for my own work (it's still pretty controversial to claim that animals have culture, although it's certainly been argued in the case of chimpanzees and some other apes), so I don't spend a lot of time thinking about the ways that my culture shapes the way I think. This article is just one example, though, of how my history and environment can affect the way I think about and experience the world. Other research on cultural effects on the mind underscore just how subtle and far-reaching these influences can be. Neuro-imaging studies have even shown that the neural activity that underlies our low-level cognition can differ from culture to culture. For example, Westerners differ from East Asians in the aspects of a scene they pay the most attention to: Americans are better at detecting changes in objects in a scene, while Japanese and Chinese people are better at finding changes in contexts. Western and East-Asian groups also show differences in the ways that they think about the "self" in relation to the group, including the way that an individual "feels" others emotions. Apparently, theory of mind, the idea of attributing emotions and thoughts to someone else, comes more easily to East Asians than to individualistic Westerners. The examples abound, and are both physiological and behavioral. For example, different regions of the brain are active in different groups when thinking about numbers of listening to music, indicating that culture may even shape the wiring of our brains!

While this research is fascinating to me, I am still unclear the implications of these cultural differences. Should we be trying to preserve culturally specific forms of mental illness? Does the identification of measurable, consistent differences between cultures reinforce stereotypes about those cultures? Do underlying differences in brain functioning among groups mean that we can never truly understand members of other cultures? I'd like to think that all of these findings are positive, and awareness of diversity is a good thing, but identifying differences between groups has been known to have some pretty horrific consequences...

Copenhagen, cougars, and cattle

2010-01-07T10:16:00.000-08:00

With the recent Copenhagen climate talks and the start of a New Year, the topic of the modern human relationship with nature has been on my mind lately. While the talk in Copenhagen was centered on the economics and politics of climate change - who gets to emit, who has to pay, and who will most likely get swallowed up by rising oceans - these topics are a poor way of describing the problems of climate change. The politicians at the conference were focusing on nature as a commodity, something that you can "cap and trade". At their most emotional, they were referring to the devastating damages to human life and livelihood that might accompany global warming. But a look at the protesters outside reveals that these aren't the issues that most concern those of us who are worried about climate change: it's the loss of Nature, in a spiritual, rather than economic sense, that concerns us. In his "Biophilia" hypothesis, E.O. Wilson suggested that we humans have a need for nature encoded in our genes, and we simply can not thrive emotionally and psychologically in entirely man-made environments. Psychological research, including several studies from Peter Kahn's lab at the University of Washington, have provided evidence for this idea. Humans are more productive, more relaxed, and generally happier when we are around nature (or even just natural images).

However, as I've mentioned before, our love of Nature is not evenly distributed. Some animals and plants are adored, while others are hated or even feared. Often, our attitudes towards natural entities are dependent on cuteness, rarity, and threat, but sometimes the cultural stance on a given animal can seem totally arbitrary. A recent article on Florida panthers in the New York Times really drove home how inconsistent an animal's reputation can be. The article describes the current state of affairs for the Florida panther: much beloved by Floridians, but extremely endangered. However, things appear to be on the upswing for the big cat, whose populations have recovered from their 1980s low point of about 20. Panthers are breeding well enough to replace the numbers of animals that are killed by cars (one of their major causes of death), and the re-population efforts have been largely fueled by sales of special Florida panther license plates. What's interesting to me is the contrast the author makes with people's attitudes toward other big cat populations around the country. Florida panthers are treated as a cuddly mascot, while mountain lions in California and other western states are often feared, and not uncommonly killed when they intrude on public areas. The difference in treatment probably has to do partly with the Florida cats' "endangered" status - everyone loves an underdog! - but also their behavior. Even though scientists have found no major genetic differences between eastern and western mountain lions or panthers, the western variety appear to be behaviorally more aggressive towards humans. California mountain lions have been known to attack and even kill human hikers and joggers - as signs around Northern California public parks never fail to remind you! Florida panthers, on the other hand, don't have much of a record for eating people. It's not clear whether this difference has to do with body size or design (maybe the Western cats are just better suited for attacking big prey) or historical food availability. Whatever the cause of the difference, it makes me wonder what will happen to the Florida panthers if their populations do bounce back completely. If there are enough cats around, it seems inevitable to me to that there will be attacks on pets, livestock, and people. Will the panthers retain the support of Floridians, or will they begin to be regarded as a pest, rather than a mascot?

Americans often dichotomous between "good" and "bad" nature. Some plants are lovingly tended in gardens, while others are doused in weedkiller. People regularly swat flies, ants, and spiders, but few would try to squash a butterfly or ladybug. Most people don't want crows at their bird feeder. And in some areas, big cats have fallen mainly on the "bad" side of the scale, while in others, they're thoroughly loved. All of these distinctions can be disastrous; although there are some animals and plants that should be controlled (invasives), a divided view of nature can prevent conservation of natural ecosystems. Hopefully the "green movement" has done something to increase awareness of the unity of nature - the importance of natural landscaping, for example, to support native insects and animal, and challenging the colonialist idea of "conquering" nature.

Speaking of conservation of plants and animals, another New York Times article describes a Rhode Island facility that is working to preserve the genetic material of many "heritage" breeds of livestock. The SVF foundation is amassing freezers full of frozen embryos from many once-popular strains of cattle, goats, and sheep that have become obsolete in the factory farming industry. Instead of goats that are hardy enough to withstand cold winters, or cattle that are good generalist milk and meat producers, large-scale animal farming has demanded specialization to only a few breeds. Growing interest in local food and sustainable farming, however, has finally won other breeds a second chance at popularity. Like a seedbank, the scientists at the SVF see this as a place to store animal genetics in case of disaster. And with so few breeds being used in factory farming (the article points out the 93% of the U.S.'s dairy cows are Holsteins), there is a lot of room for disaster. Inbreeding can lead to weak populations, and these animals are vulnerable to environmental extremes. Luckily, if all the Holsteins get wiped out by a global-warming induced heat wave, we'll be able to use the SVF to re-populate our dairy herds.

Of course, this endeavour is different than the case of the Florida panthers, as these "endangered" animals are domesticated, not native to the ecosystem. They are endangered because humans have chosen to farm other breeds, not because of habitat loss or poaching. And, whatever the breed, it's probably true that there are far too many livestock animals alive at the moment. Still, biological diversity is always a good thing, even if it's in breeds of farm animals, so here's hoping that heritage livestock and small-scale, sustainable farms keep getting more popular! I also hope that Tennessee fainting goats, included in the SVF's collection, make a comeback as a popular farm animal (Not that they were that popular to begin with...) This breed is characterized by its tendency to fall over when startled. Due to a genetic anomaly, the animals' muscles stiffen when they are frightened, causing them to topple on their sides, as if they've fainted (thus the name). Hilarious!

(A side note - my friend Hunter is starting a sustainable livestock farm in Maryland at the moment. He's raising heritage animals and will begin selling meat and eggs in a few months. For those of you back East who are interested, I'll get you his contact information as soon as they're ready!)

The Christmas Spirit

2009-12-17T11:10:00.000-08:00

Inspired by this webcomic, I decided to check if all of these papers are real... Well, it turns out that these were just a small sampling of the many, many academic articles that contain the word "Christmas" or "Holiday" in the title. A couple choice articles that got overlooked by the webcomic's author:

First - turns out, cinnamon smells better in winter than in the summer!

Title: Odor attributes change in relation to the time of the year. Cinnamon odor is more familiar and pleasant during Christmas season than summertime
Author(s): Seo HS, Buschhuter D, Hummel T
Source: APPETITE Volume: 53 Issue: 2 Pages: 222-225 Published: OCT 2009

"Aim of the present study was to examine whether odor attributes like pleasantness and familiarity change in relation to the time of the year. In the first part of the study a total Of 100 Subjects answered to questions without odor presentation whether a certain odor was more related to summertime or Christmas season. Another 41 and 51 subjects rated the familiarity and hedonicity of 12 odors either during summertime or Christmas season, respectively. Importantly, this investigation was performed at the same place within a science museum during stable environmental conditions. Subjects reported that rose odor was more related to summertime, whereas orange, cinnamon, and cloves were more associated with Christmas season with cinnamon being most intimately connected to this time of the year. Moreover, subjects showed significantly higher familiarity and pleasantness ratings when they smelled cinnamon during the Christmas season than during summertime. Taken together, this study demonstrated that attributes of some odors change throughout the year. "

Also - A study of class distinctions in Christmas decorating:

Title: Illuminations, Class Identities and the Contested Landscapes of Christmas
Author(s): Edensor T, Millington S
Source: SOCIOLOGY-THE JOURNAL OF THE BRITISH SOCIOLOGICAL ASSOCIATION Volume: 43 Issue: 1 Pages: 103-121 Published: FEB 2009

Abstract: In the last two decades, illuminating the outside of a house with multi-coloured lights has become a popular British Christmas practice, typically adopted within working-class neighbourhoods and thus producing a particular geography of illumination. This article explores how such displays have become a site for class conflict mobilized around contesting ideas about spaced timed community, aesthetics and festivity, highlighting how the symbolic economy of class conflict moves across popular culture. We focus upon two contrasting class-making practices evoking conflicting cultural values. First, we examine the themes prevalent in negative media representations of Christmas lights, notably the expression of disgust which foregrounds the working-class stereotyped the 'chav'. Second, we analyse the motivations of displayers, exploring how the illuminations are imbued with idealistic notions about conviviality and generosity.

And my personal favorite (the most holiday-cheer filled of all):

Title: A FOODBORNE OUTBREAK OF NOROVIRUS GASTROENTERITIS ASSOCIATED WITH A CHRISTMAS DINNER IN PORTO, PORTUGAL, DECEMBER 2008
Author(s): Mesquita JR, Nascimento MSJ
Source: EUROSURVEILLANCE Volume: 14 Issue: 41 Pages: 19-21 Published: OCT 15 2009

"An outbreak of acute norovirus gastroenteritis was detected and epidemiologically linked to a Christmas dinner reunion of 22 recent graduate students in a restaurant in Porto, Portugal, in December 2008. A retrospective cohort study was carried out using online standardised questionnaires. Sixteen primary and three secondary cases were identified and the risk ratios with 95% confidence intervals for each food item were calculated. The response rate to the online questionnaires was 96%. The outbreak met all four Kaplan's criteria and the attack rate was 73%. Norovirus GII.4 2006b was detected in stools and emesis samples of two primary cases. The ingestion of soup and lettuce salad was considered a risk factor for this norovirus outbreak, as determined by statistical analysis. Our investigation demonstrated two routes of transmission of norovirus starting with foodborne exposure followed by secondary person-to-person spread. To our knowledge this is the first study identifying norovirus as the causative agent of a foodborne outbreak in Portugal."

Only a group of graduate students would turn holiday food poisoning into an academic paper, right?

A search of articles about "Hanukkah", by the way, yielded almost no scientific articles. The best I could find was this:

Title: ABSENCE OF GENETIC-LINKAGE OF THE GENES FOR HERMANSKY-PUDLAK SYNDROME AND HUMAN HANUKKAH FACTOR - RELEVANCE TO POSTULATED HOMOLOGOUS MURINE COAT-COLOR MUTATIONS

Author(s): HOLCOMBE RF, YOUNG A, BETZING K, et al.
Source: CLINICAL RESEARCH Volume: 39 Issue: 4 Pages: A860-A860 Published: DEC 1991

There was no abstract available, but it sounds like something called "Hanukkah factor" (which appears to be a pre-cursor to an immune system peptide?) is related to mouse fur coat color somehow...

As usual, in the battle of the winter holidays, Christmas wins this one. Jewish scientists, I know you're out there! Get working on this!

Cannibalism in our past?

2009-12-07T15:21:00.000-08:00

Two in two days! You can tell the quarter's winding down at school... I just wanted to post a link to this article from the BBC. I think the title pretty much says it all: "Ancient site reveals signs of mass cannibalism". Apparently, archaeologists exploring a mass burial site in Germany have found evidence that about 500 of the bodies had been mutilated and possibly cannibalized. The scientists found that the bones of the bodies had been intentionally cut and broken, in the same manner as those of spit-roasted animal carcasses from that time. Other archaeologists seem skeptical about the cannibalism part, pointing out that the roasting could have been part of a burial ritual to remove the flesh. However, the researchers also have some evidence that the bones were gnawed on... The burial site is more than 7000 years old, coinciding with the beginnings of agriculture in Europe.

The BBC's science reporter offers a relatively tame explanation for the finding: perhaps the cannibalism occurred during a period of extreme famine. At Wired, however, the scientists' theory is explained: they believe the bodies are victims of ceremonial sacrifices performed during a decades-long period of political and social unrest in central Europe. Apparently there are other cases of mass slaughter around Europe from this time, as well, though none show the cannibalism evident in these corpses. Other scientists claim that this was just a ceremonial reburial, and dismiss the evidence the bones were chewed. If you are at all interested, the Wired article describes in gruesome detail exactly how the bodies were mutilated.... ugh.

Historically, it was popular to accuse humans of being the only creatures that practice such atrocities on their own kind. As Mark Twain famously put it, "Man is the only animal that deals in that atrocity of atrocities, War. He is the only one that gathers his brethren about him and goes forth in cold blood and calm pulse to exterminate his kind. He is the only animal that for sordid wages will march out...and help to slaughter strangers of his own species who have done him no harm and with whom he has no quarrel." Konrad Lorenz, the father of ethology, made similar statements. However, further experience has shown that other animals can be just as nasty as we humans... well, maybe not just as nasty, but pretty unsavory. Twain was wrong on the whole "War" claim, for one: chimpanzee troops have been known to wage lethal attacks on non-members.

I bring this up because it turns out that wild chimpanzees (our closest relatives) have also been known to be cannibals. Infanticide is fairly widespread in the animal world, but it turns out that chimps are one of the few species that also eats the dead bodies of murdered infants.

So, the finding of this burial site (assuming it does represent a case of ancient cannibalism) brings up a few difficult questions. Is this an illustration of the worst in humans - our ability to perform atrocities on our own kind? Or is it evidence of our animal nature? Is this type of genocide uniquely human, emerging in this case along with other typical "human" behaviors, like farming? Or is this an example of a behavior from our deep evolutionary past, and, perhaps, tendencies we might be able to "outgrow" or overcome? Human behavior in the past century has certainly given little sign of improvement in the atrocity department, and some the Cormac McCarthy's view on the matter in new movie "The Road"certainly offers us a worst-case scenario (the movie shows a post-apocalyptic world in which nothing can grow and cannibalism is rampant). For the sake of the 6 billion of us on this planet, and after the terror of that movie, I can only hope this is not some insurmountable aspect of our animal nature.

Did social climbing give us bigger brains?

2009-12-06T11:31:00.000-08:00

I've been reading some papers on social structures in primates lately - mostly because I was asked to give a short lecture on the topic last week. However, I've been thinking about this topic more broadly, as I try to relate some of my own research on temperament to differences in sociality between species. The question I'm tackling at the moment is: what differences might you expect to see in individual temperament between species with very different dominance systems? The answers I'm getting aren't all that surprising - monkeys that have a stricter dominance system (with more aggression) tend to be more aggressive and more fearful on average than monkeys that come from less aggressive, more affiliative species. But I'm still not sure what that means about the nature of temperament itself... answers to come, I suppose...

Anyway, in all my primate sociality reading, I rediscovered a really interesting theory about intelligence. According to this idea, called the theory of Machiavellian Intelligence, we owe our big brains to our complex social systems. Basically, the idea goes, social living is good for the group, but can be bad for the individual. If you're low ranking within a dominance system, you're going to have limited access to mating and to food - in evolutionary terms, you don't have much of a shot of passing on your genes, so you've got low fitness. However, if you can figure out a way to beat the system - to increase your rank, or gain access to that sex and food you're missing out on - you'll no longer be an evolutionary nobody. One way to accomplish this is by increasing your smarts. Individuals born with greater cognitive abilities are going to be better able to make the dominance system work for them, and so are going to be better able to pass on those "smart genes" to their offspring -leading to greater and greater intelligence in future generations, presumably. Some evidence that this may be the case comes from the fact that there is a link between social living and intelligence: all of our textbook examples of "smart" animals also have complex group interactions (i.e., primates, whales, elephants, crows, dogs).

Of course, it can be a bit of a chicken-and-egg question : is intelligence an adaptation to complex sociality, or do complicated social interactions come about as a result of being smarter? The answer, I'd guess, is probably both. intelligence and social maneuvering are probably entwined in an evolutionary feedback loop, where the smart survive, and their smart offspring figure out new, even smarter ways to exploit the social situation.

While there are tons of theories out there as to why we humans became so smart (most of them not mutually exclusive, by the way), I find the idea of Machiavellian Intelligence really compelling simply because the interactions we witness in social animals are so incredibly complex. Baboons, for example, though not the smartest of our primate relatives, give us some pretty impressive demonstrations of social cunning. In Hamadryas baboons, which usually live in harems run by a single, dominant male, the "cat-fighting" among the female group members is soap opera-worthy. Females compete to be the "favorite" of the male, which basically amounts to having the most access to him, for both mating and grooming. A lot of the female interactions to get close to the male are fairly straightforward - aggressive threat displays, chasing and attacking rivals. But one particularly interesting and "smart" strategy is the "protected threat", wherein the female garners the male's support in her attack of her rival by presenting to him (offering a mating) while simultaneously threatening another female. This is a very complex interaction, if you think about it, for a number of reasons. First, it demonstrates the female's knowledge of where she stands on the dominance hierarchy, relative to other females. The protected threat strategy might not work against a female who is much higher ranking, but would only be useful against a female who is similar in rank (i.e., if the threaten-er greatly outranks the threaten-ee, she probably doesn't need the male's help). It also suggests an ability to attribute motives to the male - in a way, a trade is being proposed: sex in return for assistance.

Such trades turn out to be very common in primates. Sex is often used as a bartering tool, most famously in bonobos, but grooming turns out to be an even more important form of behavioral currency. Recent studies have confirmed that grooming is often exchanged for access to resources and protection or alliance in later disputes. A really interesting study by French scientists found that the "value" of grooming even follows basic economic principles: individuals will be groomed more if there is a greater demand or more limited supply of the service they offer. In the French study, one low ranking female monkey was trained to open a container of food that the other monkeys couldn't open. When she was the sole supplier of that service, she was suddenly being groomed left and right. When the researchers trained another monkey to open the box, each of the two "suppliers" received half as many groomings as the first monkey did when she was the only one who could open the container.

Other examples of complex interactions abound. While early studies of primate sociality focused on the idea of linear dominance - where individual A is higher ranking than B, and both A and B are higher than C, etc. - it is becoming more and more important that alliances and coalitions are very important to shaping primate societies. In fact, in many species, groups are ruled not by a single alpha male, but by a coalition of several males, who work together to keep control of the group against rivals and invaders. Such teamwork obviously requires complex communication - the males have to establish a relationship so that they know their partners won't turn against them later. Even lower ranking baboons perform similar teamwork to gain access to reproductively receptive females from dominant males - a clear example of how being socially savvy might proffer a fitness benefit.

Clearly, animals are capable of some pretty impressive social maneuvering. And as some of the proponents of Machiavellian Intelligence point out, many of the cognitive abilities that we consider hallmarks of high intelligence in animals - theory of mind (the ability to imagine what another individual is thinking or experiencing), learning, and problem solving abilities, like transitive inference - can all be related to social interactions. Most interestingly, some studies have suggested that nonhuman primates perform better on "intelligence" tasks when they are framed in the context of a social interaction - remembering monkey faces as opposed to abstract shapes, for example. This in particular suggests to me that animal intelligence is intimately tied to social interactions. (And when I figure out how temperament fits into all this, I'll let you know...)

Art origins: animal edition

2009-11-27T20:06:00.000-08:00

I've been accused of bias in my speculations on the origins of art: perhaps, as a hipster-y girl, I am simply attracted to artists myself. I'll admit straight up that that's true, and I agree that it undermines my claims that there is some deep, evolutionary appeal to artistic talent in a potential mate. I like artists, so it's fishy that I should claim that all women inherently like artists. So, for an objective opinion, I'll turn to a group that I share almost nothing in common with, beyond my female-ness: lady bowerbirds.

Bowerbirds are a family o f birds found in Australia and Papua New Guinea that give a different twist on art as a mating behavior. Passerine birds (the song birds, or perching birds - most birds, in fact, including bowerbirds) are famous for their mating rituals. Birds like sparrows sing their hearts out to attract a mate, while others, like the Bird of Paradise, perform bizarre dances. Male bowerbirds have their own strategy: they basically create elaborately decorated bachelor pads to woo potential mates. The structures that the males create are not nests - they are used purely for impressing the ladies. Female bowerbirds will fly from one structure (or "bower") to another, comparing, and when they find the most impressive, they will promptly mate with its creator, then leave to lay their eggs and begin life as a single mother. Thus, the males are freed from any paternal responsibility (no child support here!), and, as a result, are free to mate with as many females as they can. What's unique about this system, however, is that the male's luck with the ladies is entirely dependent on his ability to make a good-looking bower - his artistic ability, if you will.

Now, it may seem like a jump to call a bird's mating accessory "art", but bowerbirds seem to bring a sense of aesthetics to their work. Males spend hours or days working on their creations, and often create structures many times their own size (the Great Bowerbird makes a sort of "hut", large enough for a human to fit inside!). What's more, beyond creating these structures from twigs and sticks, the birds also spend an enormous amount of time decorating them. Birds will gather special objects from their environments - things like shells, stones, flowers and berries, although more and more frequently, decorations will include pieces of human trash. The birds of many species seem to have an affinity for blue and shiny objects. Then, once he's assembled his collection, the male will arrange and rearrange it, getting every item just so. Males apparently show individual variation in their tastes and arrangements, and females are selecting their mates based on these differences. What's "sexy" or "artistic" to one female tends to be attractive to others, so it turns out that the males with the best bowers (the best artists, if you will), get all the matings.

Now, despite the parallel between the bowerbirds' creations and human art, there's no reason to suspect that these behaviors were inherited from a common ancestor (especially considering our last common ancestor with birds would have been some sort of reptile - hard to attribute aesthetic tendencies there), or that artistic behavior in humans is exactly the "same" as in birds. However, if something like art has sprung up in this system as an indicator of a potential mates' fitness or abilities or good genes, then perhaps it's not too much of a stretch to imagine it could pop up in our own species.

The other white meat

2009-11-16T21:56:00.000-08:00

Maybe you heard: pigs are smart. It's one of those commonly cited scientific snippets that has worked its way into popular discourse, one that you hear often (with no support or explanation offered to back it up), and, as a result of repetition, accept: pigs are smarter than dogs. Now, some of these so-called "facts" are utter bullshit - "we only use 10% of our brain capacity", for example. What does that even mean? In this day and age, when brain imaging studies can show us that activity takes place in every part of the brain, when we've even mapped the brain's functions, that fact that you still hear this so often is incredibly irritating. But I digress...

So, unlike the "10% of the brain" hacks, it turns out those people who told you pigs are smart were actually on to something. Scientists studying cognition have finally turned away from their favorite lab subjects (primates, dogs, and crows, mostly) and given pigs the chance to prove themselves. Now, it doesn't look like pigs are going to be winning chess championships anytime soon - there's no evidence (yet) that they've got the cognitive sophistication of, say, a chimpanzee. But some of the findings might just make you think twice about eating bacon...

A recent article in the New York Times nicely summarizes some of the research that's emerged on pig's intelligence. The most recent study, published in the journal Animal Behaviour, showed that pigs could learn to use a mirror to find food. This task involved a food item that was hidden out of sight, behind a barrier; in order to access the food, the pigs had to look in a mirror, remember what they saw, and then use the mirror image as a "map" to navigate through the lab space and find the hidden treat. I've never tried this with a toddler, but I'd predict a 3-year-old would have some trouble with this. Pigs have also been shown to be pretty shrewd when it comes to social interactions (the social/cognitive connection pops up again!). In a series of articles in Animal Behaviour, researchers showed that in social situations where one pig is "informed" about the location of a food source and a second pig is "naive", a couple of interesting dynamics emerge. For one, the naive pig knows to follow the informed pig straight to the treat. However, the informed pig is also less likely to go straight to the food if it senses it's being followed; instead, it will "throw off" the pig on its tail, so that it can hog the food to itself (puns intended).

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Pigs have even been taught to play video games with their snouts. Granted, the game the pig's playing in this video doesn't look that fun or complicated (it's guiding a ball into a blue patch that appears at varying locations on the screen). But, as Jameson pointed out, it's basically the same concept as Mario Kart. So maybe not chess champions, but I wouldn't be surprised if a well-trained pig could become a serious gamer (I'd challenge it to the Moo Moo Farm track, obv.)

All in all, it's clear that pigs are a fairly cognitively complex animal. What's amazing to me is that their smarts are so ignored. While people love monkeys and dogs, and freely admire the intelligence of those animals, some of the other smarty-pants of the animal kingdom get no recognition. Crows are somewhat in the same boat - hated and feared, often hunted or abused. But pigs - considering how sensitive and intelligent they appear to be, it's unbelievable that they're such a large part of most Americans' diets. Most Westerners would be horrified at the thought of eating a monkey or a dog, but pigs are ubiquitous (literally - some asshole just invented a product called "Bakon Vodka"). I try not to be a proselytizing vegan - I think food choices are very personal, and everyone should be free to make their own decisions - but I do feel like those decisions are only valid if they're based on knowledge. And I bet if more people knew how amazing pigs are, they'd be drinking a lot less bacon-flavored vodka.... or at least, I'd like to believe that we would show that kind of respect and consideration for other animals that have so much in common with us.

Update on the LHC

2009-11-16T21:44:00.001-08:00

Even though it has nothing to do with behavior, and my linking it to philosophy of science was shaky at best, I am a little obsessed with the story of the Cern Large Hadron Collider. I recently mentioned the bizarre theory that a couple of physicists have put forth, that the mysterious Higg's boson (or "God particle"), which the LHC is intended to produce and study, is somehow "cursing" the collider, foiling its own creation. Their theory, from my understanding, involves time travel and a subatomic particle with magical powers, so of course it's interesting. Part of their "evidence" was that the LHC, like previous large colliders that have set out to create the Higg's boson, has met with an unusually persistent run of bad luck. First, the enormous machine shut down shortly after it was completed, due to a magnet malfunction. The repairs finished recently, but, in an even odder twist, the machine has broken again already, due to.... a piece of baguette? Apparently a bird dropped the piece of bread into the machinery, so now the collider is "in the shop" again - and the Higg's boson eludes the physicists yet again.

Justice for all!

2009-11-10T16:32:00.000-08:00

Do these Rhesus macaques have a sense of fairness?

Many of us have experienced that sense of indignation and anger when we feel that we are not being treated fairly. A person in power might be favoring someone else, or maybe you are being being judged more harshly than you deserve. For me, these situations often lead me to examine my own feelings of entitlement or jealousy - some very human introspection. However, it seems that the emotions that prompted that introspection are not at all unique to humans. Several experiments over the past few years have shown that other animals also share a sense of "fairness", and, like humans, being treated unjustly pisses them off!

The first of these studies was published in Nature back in 2003, and examined "fairness" in capuchin monkeys. In the study, monkeys were trained to exchange a rock for a treat - usually a piece of cucumber. However, some monkeys were given grapes for doing the same task - a better reward for the same amount of work, from a monkey's point of view. The study found that when monkeys observed others getting this type of preferential treatment, they "went on strike" and refused to take part in the experiment anymore. Often, they would refuse to eat their cucumber slices, or would even throw them back at the human researchers. Obviously, the monkeys were not only aware of the disparity in rewards - they were deeply "offended" by it!

A more recent study has found a similar behavior in dogs. In this 2008 PNAS study, researchers asked dogs to shake paws, instead of exchanging a token for food. The test subjects were given either a low-value reward or no reward for performing the task. At the same time, a test partner performed the same task and received either a low-value or high-value reward (bread vs. sausage). The results from this study imply that dogs aren't as socially cued-in as monkeys - dogs didn't seem to mind if they received only bread while their partner received sausage. However, dogs did have some expectation of fairness: they refused to participate if they were not being rewarded at all and their partner was. In a control study, the researchers found that dogs would happily shake paws with no expectation of reward on their own; it was only when they saw that someone else was being favored that they gave up on the task. Again, unlike the monkeys, dogs didn't seem to mind (or be aware of) a difference in the quality of their rewards as compared to their partners', but they did notice when the rewards were unequally distributed.

Together, these studies suggest that a sense of "fairness" is common to social animals. Sarah Brosnan, the author of the capuchin paper, suggests that a sense of justice might be an evolutionarily ancient trait - something that we humans inherited from a primate ancestor. I'd say the evidence for this claim is still unclear - we do know that we share an innate sense of "equality" with some species of monkeys, chimpanzees, and dogs, but no one has yet established how widespread this behavior is in the animal kingdom. Until we know if fairness is shared by other animals, or by most primates, it's too soon to know if we inherited this trait or if it evolved multiple times. The fact that dogs respond the same way as monkeys leads me to believe that it may be the latter - this may be a behavior that sprung up along with complex social behavior several times in evolutionary history. This makes sense - being aware of what others are doing and what rewards they are receiving would be important in any sort of social setting. What's more, there's evidence that other complex cognitive abilities, like problem solving, have evolved multiple times in social creatures like primates, dolphins, and crows. It seems that there's just something about sociality that makes animals "smart" (that is, smart in the way that humans are).

I mentioned that this sense of equality has been found in chimpanzees as well - not too surprising, given that it's seen in less cognitively complex animals like monkeys and dogs. But chimps actually go a step beyond what's been seen in monkeys: they not only get mad when they see injustice, but they get even. In a 2007 study, researchers found that chimpanzees will punish other animals that treat them unfairly. In the experiment, the chimps were taught to pull a rope to make a table holding a food source collapse, making the food inaccessible. The researchers then either moved the table away from the chimps themselves, or allowed another chimp to take the food. The result? Chimpanzees were most likely to collapse the table when another chimp took the food - apparently, they could tolerate unfairness from the human testers, but not from a con-specific! This experiment indicates that chimpanzees not only feel a sense of fairness, they also desire revenge when they feel another animal has taken advantage of them.

The take-away message from all of these studies? Don't try to take advantage of a chimpanzee, because they're on to you. Seriously, I think there's always something to be said for being aware of the "animalistic" nature of many of our emotions. A lot of people feel cheapened by these sorts of studies - as if the fact that monkeys and dogs are aware of equality somehow lessens our own sense of justice. However, if you think about it another way, these sorts of studies actually emphasize our humanity; by showing how we are like animals, we also illustrate how we are able to surpass other animals. Unlike monkeys, we are able to decide what constitutes a "real" injustice, we are sophisticated enough to sometimes give up a reward in the name of altruism. Moreover, knowing that a sense of fairness exists in other animals justifies our own obsession with justice; instead of appealing to some abstract Platonic ideal to defend why we should have equality in our interactions and societies, we can just turn to evolution for the answer. Justice is important to us because we were shaped that way by natural selection, it's part of our sociality; and as something that's hardwired into our brains, it should be defended.

More thoughts on art

2009-11-06T08:18:00.000-08:00

This might be kind of a lazy post, but I just wanted to respond to some really great comments from Juan-Cristobal and Chris on my last topic. I also wanted to assure you all that I'm going to ramp up the posting frequency again. I know I've let it slip lately, but I turned in a grant application yesterday, so that should free up some time. Don't worry, I'll get the animal facts flowing again!

So, in the comments from my last post, Juan-Cristobal asked a simple but profound question: why are we assuming that the males are the ones making these hand-axes? Is there any chance the females could have been making them? I read that and immediately blushed, because I realized how at odds evolutionary biology can sometimes be feminism; there is a certain male-oriented slant to the way we think about mating which I often buy into without examining. So, here is the examining: evolutionary thought on mate choice often assumes that males are trying to impress females and females are being picky in who they'll mate with. This assumption is based partly on observations (we do see a lot of male-male competition for females - think rams butting heads or elephant seals ripping each other apart or male song birds trying to outdo each other) and partly on energetics. When it comes down to it, females provide more energy to their potential offspring than males - eggs simply "cost" more than sperm. If you add in the energetic cost of gestation in mammals and then nursing, and, in humans years and years of parental care, that's one big investment. If you're going to put in that kind of energy and time, you want to be sure you're raising a child that's going to do well. You want to be sure you give that child the best genes possible, so you are very picky about who you'll actually mate with. On the other hand, if you're a male, unless you are co-parenting (which is rare among mammals) you're pretty much willing to mate with anyone. Sperm doesn't cost you that much, and you're not going to stick around to help with baby, so you're best strategy, in terms of upping your reproductive success, is to mate with as many ladies as possible. So, in general, we assume males will mate with just anyone, and females will be very choosy. For the most part this assumption generally works - it explains behavior in a lot of animals. And when we see cases where the males are providing a substantial amount of energy to their future offspring, they tend to be more picky, confirming our idea that energetic investment has something to do with this process.

But, the question is, how broadly can you apply this simple formula to humans? For one thing, we do tend to have co-parenting, and anthropologists think that some form of social monogamy emerged long ago in our evolutionary past. If you're going to devote yourself to one female and put in a lot of time raising your children together, it makes sense that the man would also be pretty picky about his mate choice. You might expect female-female competition to emerge in this situation. However, I don't think this is the case. Obviously women do compete for male attention, but the rules of the competition are different - it's not head on, testosterone-fueled, one-upping each other, usually, but something more subtle. And, I'd say that it's probably gotten less subtle in the last century or two, as women's rights slowly inched towards equality in the Western world. Women may be behaving more and more like men when it comes to mate choice, but I feel like that's culturally, rather than biologically driven (though I could well be wrong). So to me, it doesn't feel probable that women were making hand axes to display and try to win mates.

But, that doesn't mean females weren't making hand-axes, just that if that's the case, maybe we should throw out the mating story. What if hand-axes were made by everyone, as sort of a social bonding exercise (kind of like craft night, I guess....). Perhaps these objects were used in some sort of group ceremony, or perhaps they simply helped identify which in the group were the most dexterous and artistic - not so that these individuals could get more mates, but so that they could help the group with certain tasks. In the "ceremony" scenario, maybe everyone making hand-axes and performing some sort of ritual with them helped create social cohesion, which in turn created better group unity, less tensions within the group, and a better likelihood that everyone would work together to get food, raise children, and protect from predators and attackers. In the "talent-search" scenario, maybe identifying talented individuals (male OR female), the group could begin to partition labor, increasing overall group efficiency. Both of these seem plausible to me (a non-anthropologist... so if anyone has problems with these hypotheses, fill me in!), and both include females. Of course, both are basically models of "group selection", which has long been a dirty word in evolutionary biology. But, I think when applied to complex animals like early hominids, group selection might just work.

Anyway, the point is that there are several ways that females could have been making those axes, and the sexual selection explanation is certainly not the only answer. As a female scientist, I should be careful not to undermine my own sex in buying into some of these ideas!

On to the next point: Chris suggested that maybe artistic ability isn't adaptive at all - maybe it's just "the occasional over-expression of the less extreme 'handicraft' traits that ARE adaptive". Good point - and another good shot at evolutionary biology. Not only is it sexist, it also assumes EVERYTHING is adaptive. Stephen Jay Gould pointed this out back in 1979, and even proposed a term for these things that are useful, but not necessarily selected for: spandrels. The term comes from architecture, and describes the decorated curved pieces of masonry that support a dome. The spandrels were not built to be decorative - they're a necessary to support the dome - but since they're there, they become beautiful in their own right. Similarly, something like artistic ability might have just arisen from some more practical trait or traits: maybe manual dexterity combined with creative problem solving equals art. So artistic ability didn't necessarily emerge to fill an adaptive purpose. However, I'd argue that by the time those hand-axes were being made, there was some "purpose" or adaptive advantage to the trait. Enormous numbers of those axes were produced, and it doesn't make sense that that would just be a non-adaptive "hobby" of bored hominids - why waste all that time and energy if they don't serve some kind of purpose? Now, again, I think I was wrong to assume the only purpose they could serve would be in attracting a mate - maybe they increase fitness in other ways, as mentioned above. And of course, if the anthropologists are wrong, and these axes were actually used as tools, not art, then the whole example is moot.

Still, assuming that the anthropologists have it right, then there must be some adaptive value to making art. The fact that art is a human universal also supports this idea; why would artistry be so developed in all cultures if it was just a spandrel? Around the world, people spend enormous amounts of time producing art, so just based on an optimality theory (that animals ultimately are trying to optimize their fitness), there must be some advantage to it. So, though it's totally likely that artistic ability emerged as a spandrel, it probably became adaptive at some point. But, again, it's always good to point out when we (I) are making assumptions; there's a lot of set ways of thinking about evolution. Most of those are based on evidence, and have make good predictions, but that doesn't mean they're always right. Thanks, you guys, for challenging me and contributing another perspective!

The evolution of art

2009-10-26T22:27:00.000-07:00

I've speculated a little before on the possible origins of visual art. A recent article in the New York Times gave another take on the topic. The piece, by New Zealand philosopher Denis Dutton, criticizes the conceptual art movement of the past half century (picking especially on Damien Hirst, who in 2004 sold a shark in formaldehyde for 50,000 pounds, setting a record for the most expensive work by a living artist. According to Wikipedia, Hirst's record has since been broken by Jasper Johns.) After a thorough attack on Hirst, Dutton goes on to claim that the age of conceptual art is over, and that art in the future will swing back towards artwork that is actually the product of an artisan - that is, art that takes some skill to produce. In making this claim, Dutton gives an evolutionary explanation for the value of art, why we have it at all.

According to Dutton, the oldest works of art predate the famous cave paintings of the Lascaux, and even predate Homo sapiens. Dutton claims that some of the many 2.5 million year old hand axes from the Olduvai Gorge in Africa are actually intended as art objects. He explains that while these axes may appear to be tools, they were actually intended to be appreciated for their aesthetic value. The evidence: the axes were created in far greater numbers than they could have been used, they often show no signs of wear, and, compared to other axes from the same time, they are impractically oversized, with quite delicate blades. Perhaps, Dutton proposes, these were fitness symbols, used in displays by males to help impress females and win mates. Basically, he argues, artistic skill is inherently sexy to us, and thus the roots of art are in its value for attracting a mate.

You may have noted that a lot of human behaviors get tagged as potential mate displays, ways of attracting and impressing the opposite sex. I've mentioned the supposed display value of brand name products, for example, as well as the mating benefits that might come from musical talent. This is such a common claim in evolutionary psychology and anthropology that it's almost passe - after all, there's little way to scientifically gather evidence for these behavior's mate-attracting powers today, with so many confounding factors attached. True, pop culture does often construe artists as "sexy", but also as crazy, poor, and sexually promiscuous, all of which, one would assume, would argue AGAINST choosing a mate based on artistic ability. It's almost impossible to tease apart these strands and actually test whether any of these stereotypes have truth to them (although there is some evidence that artistic talent is associated with mental illness, and, of course, if you're not Damien Hirst it can be hard to get rich as an artist).

Just thinking through how this would work, however, it does seem plausible that hand axes could have been used as a signal in mate choice by our ancestors. As a display of fitness, a hand axe might actually offer some more useful information than traditional animal displays like a peacock's tail or a sparrow's song. Imagine that you're a female Homo erectus, trying to choose a mate from the several eligible bachelors vying for your affections. If you're going to settle down with a guy (assuming a semi-monogamous mating strategy for early hominids - a claim which I hope I'll get to talk about in a post in the near future), you want to make sure he'll be able to provide for you so you can make children that will survive to adulthood. What's more, you want those children to have the skills to survive and reproduce themselves - if they're boys, you want them to be able to attract a mate when they grow up (these types of scenarios usually assume that females are in demand and can find a mate if they want to). Given all these concerns, you could do worse than to use a sample of your suitors' handiwork as a deciding factor in your choice of a beau. After all, if he's good at making special, artistic hand axes, he's probably good at making other tools at well - which might imply that he's good at using those tools to provide food to you and your future babies. More abstractly, a talent for tool making might just mean that he also has good problem solving skills (or is at least a notch or two smarter than your other options) - possible advantages which again might help him in finding food and outwitting predators to help you and your children survive, and also might be genetically passed on to your kids. Finally, in what's known as the "sexy sons" hypothesis (really), the fact that his artistic talent is hot to you might mean that the sons you produce with him will grow up to be artistic (and thus "hot") themselves, increasing their reproductive success.

In this example, it's easy for me to see how artistic skill could be used as a signal in attracting a mate, but I have to say, it's not because Mr. Dutton laid it out for me. Like many people who hypothesize about the adaptive value of behaviors, Dutton just claims that Acheulian hand axes might be adaptive in attracting a mate - and leaves it there. I'm sure his reasoning on the matter was similar to mine, but not everyone is trained in evolutionary theory (in fact, a scary number of Americans have little or no understanding of evolutionary theory!) Maybe it's the media's fault for sloppy coverage, but I feel like it's perhaps too easy to just claim some behavior or tendency is adaptive and leave it at that. For an example, today in my cognitive development class, the lecturer made a comment that some theorists believe that infants are born with innate abilities and knowledge - for example, the knowledge that objects are solid and can't pass through each other - and that these abilities were pre-programmed because that was adaptive. Adaptive how? Surely someone has thought that one through, but I still am unsure how knowing objects are solid right off the bat is going to increase a baby's chances of survival. Some applications of evolutionary thinking to human behavior seem more legitimate than others; for me, I'm not sold on the baby knowledge claim, but the hand axes? That one rings true.

Wily orangutans and sloppy statisticians

2009-10-23T22:04:00.000-07:00

Today in Animal Behavior Journal Club, we discussed a recent study that claims to have found a new kind of culturally transmitted tool use in orangutans: basically, a voice modulator. The article, in the Proceedings of the Royal Society B, reports that orangs in certain geographic areas are using leaves to modify one of their vocalizations, called a "kiss squeak". This cute kissing noise seems to be a response to would-be predators (although from my understanding of the article, it has only been observed as a response to humans!), and appears to be part of the vocal repertoire of all orangs. Sometimes, the animals will stick a hand over their mouth the modify the sound, and in this particular group, they will cover their mouths with a bunch of leaves. The researchers speculate that this is done to modify the frequency of the sound, making it sound lower. The theory here is that the animals are trying to seem more intimidating to a predator - because bigger animals tend to have lower calls, the researchers suggest that small individuals might use this technique to make themselves seem larger. In short, the animals are using this tool (the leaves) to change their vocalizations and deceive would-be predators (or human scientists....)

The orangutans have the same strategy as the women attending the stoning in the Life of Brian:

Now, this is a sexy article, because it involves a bunch of topics that would pique any animal behaviorist's interest: great apes, tool use, culture, deception. However, as our discussion today showed, the research - and the theory - is full of holes. For example, the researchers never demonstrate that this is an alarm call - it just appears in response to humans (prompting some of us to wonder if it might actually be a human-specific vocalization). If they're not sure what the purpose of the call is, it's hard to make a good case for how the leaf-use would fool predators. What's more, the idea that the lower sound might convey "Hey, I'm big!" isn't well supported, since the orangs apparently utter these calls in sequence with a bunch of unmodified calls. If anything, the deception MIGHT be : "There are a bunch of us up here! Don't even try to mess with us!", since the single animal is creating kiss squeaks at different frequencies in succession. And I'll just mention, for good measure, that the researchers only vaguely mention how this behavior might be considered "cultural" - in that it's only found in some orang groups, but not all - but don't elaborate or give any details on that point. Sloppy all around.

But what's really sloppy here are the statistics. I guess this is common when making observations of (endangered) wild animals, but the sample size is minuscule (less than 20), and only 5 of the observed orangs used leaves to modify their kiss squeaks. That means that the researchers saw just 5 cases of this behavior, noted that it was happening in younger/smaller animals, but never in the largest males, and spun this hypothesis around those two facts (to be fair, they also did measure the frequencies of the kiss squeaks with and without leaves, to prove that the leaves really did make the sounds lower. So that's some more Science for you). Now, I don't mean to criticize their theory or say that it's wrong, but it is frustrating that a study can get so much press and be published in a respected journal when it's all fluff based around a couple of observations. Of course, it's hard to do good statistics when you're working with such a rare subject, but it is discouraging that things like this get published with no acknowledgement that the evidence is pretty thin.

I'm probably nit-picking about this because I've been taking so many statistics classes lately. I've been reading papers where authors complain condescendingly about other scientists who don't bother to take their Type I error into account when performing multiple post-hoc comparisons, or who list multiple alpha levels throughout the paper. When it comes to math, people can be incredible sticklers. And while the tone of superiority is a little annoying to me, I do see that these quantitative psychologists have a point. After all, raw data is rarely published in scientific papers, and the journal doesn't check your math. Since science, the way it's practiced today, can be dependent on coaxing pictures from numbers, this can be a problem. If you massage the numbers in the right (wrong) way, you might get them to say something that simply isn't true. That's the powerful and fun thing about statistics - and it's made dangerous by the fact that so many people don't know how to interpret numbers. Really, having TAed a stats class last winter, I realized just how much fear people can have when numbers get involved. Most laypeople, at least, are happy to just accept data as "true" if it's published, and don't question the numbers at all. Thus, it's a little worrying when things like this get published, because the media coverage and interpretation by the public isn't realistic; they're not getting that this is a highly speculative theory, based on a small number of observations, they're thinking it's a "fact". Again, I'm not opposed to this being true - I think it's a cool idea - but I think perhaps scientists and journals should be more careful to convey uncertainty when they don't really have good evidence to support their ideas.

Physics and Fate

2009-10-13T22:07:00.000-07:00

(Image of the LHC from news.bbc.co.uk. This is actually the equipment that will be used to produce the Higgs boson)

This is a little outside my realm of expertise, but so bizarre and interesting that I had to mention it. According to a New York Times write up, some physicists have come up with an incredible theory to explain the problems that have been troubling the newly built Large Hadron Collider. The collider was designed to be the world's largest and fastest particle accelerator, and lies in a hidden underground lair outside Geneva. After opening to great fanfare (including doomsday warnings from some that the collider would produce a black hole that would swallow the earth), the machinery promptly broke down. The mechanical fault (a bad connection between two magnets) set the project back a year, after years of unusually slow moving progress and bad luck. To explain the apparent jinx on the project, two scientists, Holger Bech Nielsen and Masao Ninomiya, have suggested just that - a jinx. The idea is that the particle that scientists are trying to use the collider to create - called the "Higgs boson" - is so unnatural to the balance of the universe that it is somehow able to prevent its own creation. The physicists posit time-traveling, or a sequence of backward-rippling events that would make the production of a Higgs boson impossible. Nielsen put it plainly in the Times, saying, "It must be our prediction that all Higgs producing machines shall have bad luck."

All of this sounds kind of crazy, but perhaps not much crazier than many of the claims and predictions of quantum physics. Perhaps if disaster continues to strike the Large Hadron Collider, Nielsen and Ninomiya will be taken more seriously (although I get the impression that they're respected in the physics world already). Not having a strong background in quantum physics or the time to slog through "Search for Future Influence from LHC", I'm not going to weigh in here on whether I think this theory is correct or even plausible. But it does make me think about a conversation I recently had about the role of science and the scientific method in human thinking.

First, the conversation (ok, actually it was a debate. Maybe an argument) started off with distinguishing between science and the scientific method. My thoughts on the matter: "science" is used to refer to the canonical information that we learn in school (which, my partner argued, was inherently biased because of the culture in which it was produced. Perhaps.) , while the "scientific method" refers to a specific, human strategy for understanding the world. "Science" is learned, and may be flawed, but in my opinion, "the scientific method" is inherent - a cognitive structure that we are born with - and tends to be pretty effective. To be more specific, the scientific method refers to the process of creating "theories" about the world around us (although theory is too formal a word - what I mean is ideas about what causes events, ideas that can generate predictions and explain a variety of phenomena that we observe), testing those theories, (either through formal experimentation or just noting whether or not our observations match what we would predict), and revising them as necessary. All of this, by the way, is described in a theory of cognitive development proposed by developmental psychologists Alison Gopnik and Andrew Meltzoff called "Theory theory". According to these researchers, infants are born with an innate problem solving strategy - the ability to make and test "theories" - that guides them in their understanding of the world. The formal scientific process that some adults practice is just an extension of this innate human ability. Gopnik and Meltzoff actually describe babies as "little scientists" - although they might as well call scientists "big babies". Either way, I think it's an appealing and believable idea - if, as Noam Chompsky proposed, we have innate language templates built into our brains at birth, why couldn't we also have innate problem-solving templates?

So, coming back to the physicists, I have a few thoughts. First, it seems bizarre that a process that is so carefully designed (by evolution, assumedly, and then formalized by the institution of Western Science) could result in a theory that sounds so much like Magic. I don't doubt that whatever explanations Nielsen and Ninomaya give for their theory of the "Higgs Boson of Doom" build off of other established ideas and facts, but in a way their outcome sounds comically similar to superstition - simply saying, "Hey, it looks like this particle we're trying to create is bad luck!" For that matter, it's not much different than saying "this particle can't be created because it's God's will" - although Nielsen actually acknowledges this similarity in the article.

On the other hand, the idea that the same simple cognitive process that an infant uses to understand the basic physical characteristics of the world - that objects are solid, that they fall when you drop them, that you can't see through them, etc., etc. - can tackle questions so far removed from physicality. That is, Nielsen and Ninomaya, in theorizing about the possible backwards-time effects of the Higgs boson are using the same scientific method a baby would use (according to Theory theory, anyway), but applying it to something much more abstract. Indeed, one might be skeptical that a cognitive machinery that adapted to understand the physical problems of the world would be accurate in generalizing to such an abstract dimension. In my argument about the power of science, I claimed that the scientific method is a useful and important tool in the human arsenal, but that it can't tackle all domains. Some questions (Is there a God? What is the meaning of life? What do we experience after death?)are beyond the scope of science to answer. Scientists may hypothesize about them, but there's no way to test those hypotheses, so they really are philosophies, not solid science. I proposed that this is the realm where Science and Religion can overlap, and both have an equal shot being "right", since we have no way of knowing! But here we have an example of Science infringing on this realm, physicists positing a scientific question that I would have thought unanswerable ("Is there such a thing as Fate?") Of course, they still don't seem to have quite a testable hypothesis, but it at least seems like we're gaining the ability to apply the scientific method to broader and more abstract realms. One thing's for sure: I'll be following news of the Large Hadron Collider very closely. If things continue to break down and fall apart, maybe Nielsen and Ninomaya have a point...

Seeing with new eyes...

2009-10-07T13:55:00.000-07:00

Thanks to UW researchers, this monkey can now distinguish the red cluster of dots at the center of the screen. From sciencenews.org.

In thinking about the way other animals experience the world (apparently a theme lately), I keep focusing on what they can do that we humans can't. Bats can echolocate! Dogs have many times more scent receptors than we do! Pit vipers can detect infrared radiation with their pit organs! But there's one area where we humans have most other animals (at least other mammals) beat: color vision. While many other mammals can't see any color, and others can see only limited color, humans can distinguish reds, blues,and greens - the full range of the visible spectrum of light. I don't mean to overstate the specialness of this ability - other apes and African and Asian monkeys, as well as many birds also have this ability. But for mammals, we are fairly unique in having a technicolor world.

A team of scientists at UW has recently democratized our special color-seeing abilities a bit, granting some lab monkeys the chance to see as we do. The ability to distinguish reds from greens is the mark of full color vision, or trichromatic vision. Animals that have dichromatic vision see the world in a mix of blues and greens; animals with monochromatic vision see only in black and white. The difference in the number of colors you can distinguish depends on how many types of cone cells you have in your eyes; for trichromatic vision, you need three varieties, while dichromatic vision requires two, and monochromatism just one. In this project, the researchers were able to successfully change some of the cones in the monkeys' eyes into the missing third type via gene therapy. The monkeys, which prior to the experiment could only see in blues and greens, now can distinguish red from green, as well.

As my friend Chris (who sent me the link to the article in the first place, thanks again) pointed out, it's impossible to imagine what this change in sensory experience must have felt like for those monkeys. Suddenly, the world around them held a new dimension that they had never been aware of - a broader range of colors, differentiating objects. While the monkeys can't tell us what this experience was like, maybe someday someone can - the researchers responsible have suggested that this gene therapy may be an effective treatment for colorblindness in humans (which results from having only two, instead of all three cone cells).

The possible applied therapeutic uses of this discovery have captured the headlines, but one cool angle that most of the media coverage seemed to skip over was the fact that the researchers here were effectively recapitulating the evolution of human color vision. New World monkeys (like the squirrel monkeys used in this experiment) have an unusual color vision distribution: males are color blind, with only two types of cone cells, but some females have full tri-chromatic vision. Because the genes for cone cells are encoded on the X chromosome, and females have two XX chromosomes as compared to males' single X, females basically get an extra shot at having all three cell types. While it's unclear whether the last common ancestor of old and new world primates had full color vision, one can trace the evolutionary path through which some American monkeys (especially Howler monkeys) gained full tri-color vision for all. All it would take would be a single gene mutation, some copying error that would place two different cone cell blueprints on the same chromosome. It's still unclear exactly what the benefits of this change would be - did full color vision help our ancestors pick out red fruits? Is it's advantage somehow related to the red estrus swellings in many female primates that signal fertility? I've even heard it proposed that color vision is important to humans because we are highly social animals and a lot of social communication occurs through red flushing of the face (as when we blush or turn red with anger). Whatever the reasons, it's exciting to think that we are able to apply our knowledge of genetics to follow the pathway forged by Natural Selection thousands of years ago.

This last reminds me why I love evolutionary biology so much. I've been taking a lot of psychology classes lately (thus the lack of posts, sorry), and in one class we've been discussing philosophy of science as it applies to psychology. A really interesting point is that psychologists have an inordinately hard time integrating the different levels of their analysis - that is, psychologists tend to think of behavior on the level of some sort of Freudian psychodynamics OR behaviorism (learning and avoidance) OR cultural constructs OR neurophysiology OR genetics. It's hard to bring all of those perspectives together, or even to connect a few of them. Evolutionary biologists, on the other hand, have managed to connect the very, very small (the language of DNA) and the very, very large (the long-term picture of evolution) into a single, unified picture. Psychologists really should take a look at their example.

How science reporting works

2009-09-27T20:09:00.001-07:00

This is what I try not to do...

From Saturday Morning Breakfast Cereal

Cellular cities

2009-09-23T17:47:00.000-07:00

How would you feel (yes, you, reading this right now) if I told you you aren't who you think you are? You might have a sense of self, a persona, a feeling that you control your body - but what if I told you that was all an illusion? Believe it. More and more research is revealing that we're not as in control as we think we are - often, it's the little guys who are in charge.

How little? Very, very small. Microscopic. In a bizarre reversal of the "natural order" of things, it turns out that bacteria and tiny parasites that live on and in our body can have a huge effect on our behaviors. To understand how this works, it helps to stop thinking of yourself as a single unit. You are a posse of cooperating cells, a city of tiny living things that have been programmed to live in the urban sprawl of your body. Each cell would be just as happy living alone on a Petri dish, but the mysterious forces of life make them brave the crowds and work together to make You. So, instead of thinking of bacteria as tiny puppeteers, commandeering a vessel many times their size - Lilliputians ordering Gulliver about - its better to think of them as citizens of this cellular city. Immigrants, perhaps. A little bit different than the rest of the residents, and often, with an unusually large impact on the "society".

It's also important to realize just how many of these invaders there are. What few of us realize is just how many of these foreigners we carry on our bodies. The answer is staggering: according to Olivia Judson, a science blogger at the New York Times, microbes on our bodies outnumber our own cells by a factor of 10 - so, as she points out, in reality, we are only 10% "ourselves". What's more, they are remarkably diverse. Each of your fingers hosts a different community of microbes; the species that live on your wrist are completely alien from those on your inner elbow.

With this picture in mind, it becomes easier to imagine that such tiny creatures could alter your behavior. But how do they do it? One important way is through controlling what you eat and how your body processes it. The gastrointestinal tract is a hot spot for microbes, which play a crucial role in digestion. We need them to get the nutrients from the food we eat it, just as much as they need us to act as hosts. And apparently, the resident microbes of my stomach are entirely different from those in yours - there's a great deal of variation in which little guys we host, depending on our diets, genetics, and environments. Where it gets weird is when we realize that important health and behavioral issues related to food correlate with different microbe demographics in the digestive tract. In a recent article in PLoS One, researchers found that the digestive tracts of obese and anorexic subjects both differed significantly from normal subjects. Of course, this change in microbial make-up might have started from a "top-down" decision on the individual's part (to eat more or less calories), but the total change in who's living in their intestinal neighborhoods indicates that after a while, the decisions move out of the subjects' hands. In anorexic patients, the gut has more Methanogens bacteria than normal - which, ironically, are helpful in converting calories to fat. Perhaps because of restricted caloric intake, these people end up with a gut full of bacteria that makes them more efficient at sucking calories from the food they eat - which in turn, may make them gain weight more easily, leading to a cyclical process of disordered eating. Obese patients, on the other hand, have more Lactobacillus than normal. As this microbe is associated with weight gain in animals and growth in children, it may be that having a gutful of Lactobacillus is more responsible for extreme weight gain than any choices on the individual's part!

Things get even weirder when you move outside the gut, into the brain. Radiolab on WNYC recently did a podcast on parasites that revealed some bizarre ways in which tiny animals can control our behavior. The strangest by far is the story of a parasite called Toxoplasma Gondii, which breeds exclusively in the guts of cats. The parasite has developed an elaborate reproductive life-cycle in which it is passed from the poop of cats into the stomachs of rats or other rodents - and from there uses mind control to get back into the cat's guts by making the rodents strangely attracted to cats (instead of terrified of them, as one would expect). Some speculate that T. Gondii can affect humans as well, perhaps resulting in "crazy cat ladies" (a strange, unwarranted devotion to and obsession with our pet cats). Others suspect that the parasite may cause schizophrenia in humans, and link the rise of cat ownership to the rise of the mental disorder.

A fungus erupts from the head of an ant. From www.utexas.edu

Of course, this phenomena of tiny creatures taking over larger animals is not unique to humans, or rodents. One of my favorite oft-cited examples is the fungus Cordyceps, which invades the brains of ants and basically makes them want to go to a high place. Once the ant has climbed to the highest blade of grass or stick around, the fungus finishes it off, and then uses its high elevation point as a spring board, floating down the breeze for a new target. There are a number of similar examples in insects - perhaps because their behaviors are so simple to begin with, it is easier to understand how parasites affect their behaviors than it is with something more complex, like, say, humans. But although we might not yet have identified such a straightforward example of microbial brain control in humans, that certainly doesn't mean it doesn't exist. The moral of the story? All living things are cellular cities, and sometimes it's not clear exactly who's running things.

Giant rats!

2009-09-18T08:37:00.000-07:00

Just when we start to get smug in our scientific understanding of the world, discoveries come along and illustrate just how little we know. One example: the recent discovery in Papau New Guinea of a new species of giant rat. A team of scientists poking around the inside of a crater discovered the rats, along with a host of other new animals. As one of the explorers put it, "To find new species of insects in this region isn't uncommon, but we found sixteen new frog species, one new bat species and at least three new fish, and this giant bloody rat -- the size of a cat. Amazing!" The rats are very similar to the kind you'd find in a city sewer, but much, much larger. With no natural predators (as the article explains, local tribes consider it too much effort to hike all the way up and into the volcano just to get some rat meat), they are also unafraid of humans. Scary!

Now, I know that the discovery of a new rat, while cool, may seem at odds with my first statement; the fact that somewhere in Papau New Guinea a giant rat is roaming a small area of forest will hardly change most of our lives. But what I meant wasn't so much about the impact of this particular discovery, but the fact that discoveries like this are possible. In an age when scientific thinking reigns, it's easy to believe the Religion of Science - that science has already explained everything we need to know about the world, and now we're just ironing out some final details. When we realize how much of the earth is still unexplored and that there are still many species to be discovered, it can humble us a little as to how well we know the face of our own planet. When we consider that for each new species there is a corresponding suite of behaviors to understand, an evolutionary history to explore, and an ecological impact to identify, the amount we don't know expands exponentially. And, even more, there are genomes to decode, enzymes to identify, neural pathways to map. If all the scientists on the planet focused their efforts on studying this one species of giant rat, we probably still would be left with some mysteries about its anatomy or habits or cellular structures. The amount we don't know far overshadows what we do know. And every time someone discovers something like a new "giant bloody rat", we should acknowledge the vastness of our unknowns.

A dog's world

2009-09-14T16:30:00.000-07:00

As a follow up to my last thoughts about imagining the world through another animal's (or person's) eyes, the NY Times just published a review of a book all about how dogs experience the world (Thanks, Chris, for sending the article my way!). In the book, "Inside of a Dog" (which I haven't read yet), author Alexandra Horowitz imagines what it would be like to experience a dog's umwelt. It's fascinating to think about how sensory capabilities shape your world, and even though my last post was a complaint about the impossibility of imagining another creature's experience, I still like to try.

On a sensory level, Horowitz has some cool insights into how a dog sees, smells, and hears differently from humans. For one thing, a dog's sense of smell makes our own capabilities seem like a joke. According to the article, a dog's nose has 50 times as many scent receptors sites as a human nose, and is designed such that a dog can continuously take in new smells without having to stop for breath like we do. What's more, scents are necessarily time-sensitive - they may start of weak and get stronger, or change, before eventually fading. So when a dog is experiencing the world, every sniff is infused with information about time that we humans are blind to (pun intended). Apparently dog sight is different to human vision as well, as the structure of their retinas lets them process light faster than we do. What this amounts to is a larger "number of snapshots of the world that the eye takes in every second", which, the article author suggests, is why dogs are so good at catching moving balls in mid air, or picking up on subtle human facial expressions. Small motions that our eyes can't capture are clearer to a dog because of their faster "shutter speed".

The article has some other examples of how a dog's umwelt differs from our own - it's definitely worth a read. And it offers some ideas about how those cancer dogs I mentioned earlier might be spotting the disease - simply because their senses give them access to "invisible" information.

Of course, one question is, just how invisible is this information to us? True, the very physical structure of a dog's sensory organs means that it is going to be able to smell and see more (or at least differently!) than we do. But it is interesting to consider that we don't even know all there is to know about the human umwelt. As I mentioned before, part of this has to do with subtle differences in sensory capacities between different people, depending on genes or age, but there is evidence that we aren't even able to process all of our own sensory experiences. For example, the human sense of smell is often dismissed as our weakest sense, but it is far more powerful than we realize. In experiments, humans are able to distinguish kin from non-kin by smell alone, and to pick sexual partners (judging by which smell they find most attractive) based on their immune system compatibility. Clearly, we are getting more information through our olfactory system than we give ourselves credit for.

Similarly, our visual system, while not as high-speed as a dog's, is capable of reacting to stimuli that we don't consciously register. In a set of experiments at UW, one of my fellow grad students found that a subject's visual system can distinguish between a looming stimulus that is on a path to hit them versus one that is going to be a near-miss. Although the two stimuli look almost the same, the brain is able to quickly gauge which one of them is dangerous and respond to avoid getting hit.

The main message for me from all this is that by living in our own (conscious) umwelts, we fail to understand a lot of phenomena around us. Thinking in terms of umwelt can explain some mysterious aspects of animal behavior (like the cancer sniffing dog thing), while looking at some of the sensory information we humans process unconsciously can explain our own behaviors (like why we know when to duck when something is thrown at us, or some elements of sexual attraction). Senses are central to understanding behavior, and if we forget to take them into account, we are going to miss out on a lot!

What do you see?

2009-09-10T09:50:00.000-07:00

How do others experience the world? It's a question that's puzzled scientists and philosophers for ages, and one that's almost impossible to answer. True, you can make some guesses, but you can never know for sure what the sensation of seeing, feeling, smelling, or hearing is like for another being. You might assume that another human would have a similar experience of the world to your own, but there is no fool proof way to verify that, say, two peoples' experiences of the color "blue" are the same. Moreover, because there is so much variation among people in their sensory abilities (some people are colorblind, others have perfect pitch; some are super-tasters, others have no sense of smell), it's likely that your sensory environment is slightly different to everyone else's.

The question gets even more complicated when you start to consider other animals' sensory worlds. Animal behaviorists have long been aware of these differences, and even coined a word for it: umwelt. Ignoring individual differences, German scientists in the 19th century observed that every species had different sensory capabilities, and so concluded that each type of animal must experience the world in a different way, in a species-specific, unique sensory environment (its "umwelt"). Later research only emphasized how different these umwelts can be, as scientists discovered that some animals can sense magnetic fields, or ultra-violet light, or electric fields, or heat, or sounds far beyond our own auditory range (to name just a few). The world is full of information, but every type of animal is limited to a small subset of that information by its sensory capabilities. These limitations make "umwelt" a very important concept for understanding animal behavior. It's impossible to study bird migration, for example, without understanding that birds are able to sense the Earth's magnetic fields; similarly, it would be difficult to explain how a platypus finds tiny food items in the mud of murky streams without knowing that they are able to sense electric impulses from their prey with their bills.

The problem with umwelt, however, is when we try to imagine ourselves in another species' umwelt. As I've pointed out, it's meaningless to try to imagine yourself in another humans' sensory space; it's even worse to try to filter another species' experience into terms the human mind can understand. The philosopher Thomas Nagel famously pointed this out in his paper "What is it like to be a bat?". The answer, according to Nagel, is "who knows?"

Our own experience provides the basic material for our imagination, whose range is therefore limited. It will not help to try to imagine that one has webbing on one's arms, which enables one to fly around at dusk and dawn catching insects in one's mouth; that one has very poor vision, and perceives the surrounding world by a system of reflected high-frequency sound signals; and that one spends the day hanging upside down by one's feet in an attic. In so far as I can imagine this (which is not very far), it tells me only what it would be like for me to behave as a bat behaves. But that is not the question. I want to know what it is like for a bat to be a bat. Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate to the task. I cannot perform it either by imagining

additions to my present experience, or by imagining segments gradually subtracted from it, or by imagining some combination of additions, subtractions, and modifications.

Basically, the only way to picture the experience of a bat (or another human, for that matter), is to imagine it in terms of your own experience. And the key word here is "imagine" - once you start trying to picture what it would be like to "see" objects through sound, with a bat's echolocation, then you are getting away from the bat's experience and back to your own subjective experience. The only thing that can be objectively measured here is whether or not the bat can sense different stimuli, and what sensory systems it uses to sense them. Other than that, everything is conjecture.

Despite the fact that many philosophers agree on this point, many scientists, and especially the media, often ignore it. For example, National Geographic-type publications never tire of publishing pictures showing the world through some organisms' eyes. A "bees eye" view of the world, for example, is ultraviolet and prismatic, right? Well, given what we know about bee anatomy and eye structure, that's a good guess, but we can't really be sure that a bee's view of a flower looks like this:

From the Humboldt Foundation

Here, flower A represents the human experience, and flower D the bee experience. A nice imagining, to be sure, and an illustration of the fact that bees surely see the world differently than we do... but accurate? Who knows?

With that long caveat, I'd like to start conjecturing about that first question: how do others experience the world? I heard an incredibly interesting interview on WNYC's Radiolab that (tentatively) considered that question. The fascinating thing about this piece was that it didn't address the umwelt of an exotically different animal, like a bat or a bee, but instead explored the sensory experience of other humans. In particular, the discussion was about the sensory experience of newborn human babies.

While I had naively assumed that a baby's experience would be much like my own, just with every stimulus seeming new and surprising, it turns out that baby's sensory systems are actually quite different from adults'. For example, the lens of the eye yellows with age, so babies actually experience colors differently than adults do, as their lenses are still clear. The researcher in the interview also suggested that babies auditory systems may not have yet adjusted to processing the time lapse between sounds arriving at both ears, so to a baby, all sounds may have an echo effect. Most bizarrely, apparently there is some overall system glitches in babies that causes auditory stimuli (sounds) to sometimes be processed in the visual cortex, and vice versa. In other words, all babies may have synesthesia until they get their sensory systems straightened out.

The interview was careful to make all of my earlier points - although it looks like this is what is happening in an infants brain, and we can imagine what it would be like to experience the world that way, that doesn't mean we can really know what a baby is experiencing. Still, maybe it explains why newborn babies look so constantly confused: not only is the world new, but it may be a complete psychedelic experience, full of phantom echoes and cross-modal sensations. Who wouldn't be confused by that?

Pack rat syndrome

2009-09-08T22:43:00.000-07:00

An article in the NY Times magazine on the ever-expanding self-storage industry got me thinking: what is it that makes people want to hold on to all that stuff? Why do people opt to pay monthly fees to store objects they never use, instead of just discarding them?

Now, I've passed plenty of storage facilities, usually lurking around the seedier parts of cities, or near the freeway, but I had no idea how large the industry has grown in the last decade.

According to the Times, the U.S. has 2.3 billion square feet of self-storage space, which apparently makes it “physically possible that every American could stand — all at the same time — under the total canopy of self-storage roofing.” I also hadn't realized how many people use self-storage - one out of every ten households in the country. That's an enormous amount of stuff, and illustrates some of the unsustainable aspects of our culture - the desire to keep acquiring more and more without responsibly discarding of or reusing old things. As the article points out, "Even by the early ’90s, American families had, on average, twice as many possessions as they did 25 years earlier" - and the problem has only grown in the past decade.

Of course, reluctance to part with possessions is not the only reason people use storage spaces. The article highlights several others : these spaces can be havens for people in the middle of chaotic changes, especially moves, or can store the belongings of people who are homeless. However, in large part, the phenomenon is fueled by people having too much stuff. The Times author outlines a few reasons why this might be. For example, a distorted sense of thrift makes people more willing to pay the rent for a storage unit than "lose" money reselling or donating old possessions. The plummeting price of many products, combined with a less responsible spending atmosphere has also contributed to an increase in consumerism.

So, the question is, when does keeping stuff become a problem? If you have the money to pay for a storage unit, what's the problem? Well, besides the negative environmental impact of huge storage facilities, the urge to hold on to possessions is not considered psychologically healthy. In fact, excessive hoarding is sometimes considered a psychological disorder, a manifestation of Obsessive Compulsive Disorder. However, that classification is debatable, as many more people hoard than suffer from OCD. To define hoarding on its own, then:

"Excessive (compulsive) hoarding has five prominent features: excessive acquisition of large numbers of unnecessary and often worthless objects or items; apparently irrational, emotional attachments to the objects; vigilant protection of the collection; cluttered living conditions; emotional and behavioural resistance to discarding the objects/items. The hoarding is excessive if it seriously interferes with normal daily activities, creates hazards, causes annoyance and complaints from other people or agencies." (Rachman, et.al., 2009)

In other words, hoarding is a problem when it starts to interfere with daily life. That sounds nice enough, but makes it difficult to draw the line between "normal" hoarding behavior and "excessive" hoarding. Paying rent on a storage space every month certainly represents a strong attachment to objects, a feeling that they need to be protected and a resistance to discarding them, as well as an interference to normal finances. And, as the Times article repeats several times, the majority of the objects people choose to keep in storage are, objectively, junk.

Of course, this is a problem in many psychological disorders - there are no clear boundaries between normal and abnormal behaviors. However, subtle differences do distinguish excessive hoarders from non-hoarders - or might at least act as warning signs. For one thing, people who have a problem with hoarding report feeling more attached to inanimate objects than most people do, and, correspondingly, feel less attached to other people. They also tend to be unusually afraid of losing their possessions, the same study found.

This provides one psychological explanation for what is going on with hoarders - they are somehow replacing the human relationships in their lives with inanimate objects, and thus feel unusually attached to and unable to get rid of those objects. Someone like Robert "Bowling Alone" Putnam would probably agree with me that this could be partly behind those storage unit-enthusiasts reluctance to part with their own possessions : as our way of life becomes more isolating, perhaps people are more likely to turn to objects for comfort.

On the other hand, hoarding can also be seen as a biological impulse gone awry. After all, we do see hoarding behavior in many animals, especially rodents and birds that store food for the winter. One view of compulsive hoarding in humans sees it as the same phenomenon in a different environment. In the wild, where resources are scarce, it would make sense for humans to hoard. Collecting stashes of food and other useful items probably helped our ancestors survive through lean times. But today, when stores and restaurants are virtually everywhere, this once-adaptive tendency to hold on to items is no longer relevant; in fact, it can even be maladaptive (just take a look at some pictures of the homes of compulsive hoarders, and you'll get an idea of how dangerous and unhealthy those living spaces can become).

Again, I don't mean to imply that everyone who keeps things in self-storage is a pack rat, or an excessive hoarder, but I do think it's worth noting the extent to which we've normalized hoarding. It's now ok to have so much stuff you can't fit it in your house - more stuff than you need or want. And it's acceptable to keep that stuff in hidden stashes in storage units. So, while it's not my place to say if this shift is unhealthy or "bad", I think it is important that we draw attention to it and think about what types of other cultural changes might be underlying this one. Could a less personal, more virtually based social world be triggering more attachment to objects? Could a sense of impermanence in a rapidly changing world make certain objects seem rarer, and thus more important to hold onto? Or, as the original article suggested, is this mostly an economic issue, fueled by consumerism? I don't have the answers, but it sounds like this is getting to be a problem.

Guilt, innocence, and fear

2009-09-04T12:36:00.000-07:00

For some of us, guilt is hard to escape. Sometimes you can justify all of your actions, tell yourself you've done nothing wrong, but still feel that distinct "falling" sensation in the pit of your stomach that signals otherwise. A recent study reported in the New York Times got me thinking about this inescapable quality to guilt. The study, by developmental psychologists at the University of Iowa, showed that children as young as 2 feel guilt when they suspect they've done something wrong. In the experiment, the children were given a toy that was presented as a special heirloom; it was also rigged to fall apart as soon as the child handled it. The responses of many of the children were clearly recognizable to adults as signs of guilt: squirming, avoiding the researcher's gaze, covering their faces with their hands. When asked to describe how they were feeling, the toddlers used the universal language of guilt, calling it "a sinking feeling in the tummy."

Clearly, guilt affects our behaviors from a young age. An interesting result of the study is that there appears to be a good deal of individual difference in how much guilt one feels, even among toddlers. The article seemed to imply that this difference is mostly a result of parenting methods, religious exposure, etc., but I don't see why it couldn't be a result of innate, genetically programmed differences (for that matter, I don't see how the two factors could really be separated. Perhaps people who are guilt-prone tend enforce rules, or take part in organized religion more than others. If that were the case, it would be impossible to tease apart the separate threads of nature and nurture here, unless one looked at adoption cases).

The researchers also found that children differed in innate levels of "effortful control", a finding similar to the differences in self control found in the marshmallow study at Bing. Apparently, how guilty you feel when you do something wrong is completely unrelated to your level of effortful control (how well you're able to control yourself and stop yourself from doing something wrong in the first place). However, both high guilt and high effortful control are effective in creating well behaved kids; children who scored high on either trait as toddlers were less likely to act out or hit others as kindergartners.

While the children in this study were clearly experiencing guilt as adults know it, that doesn't mean that we can attribute guilt everywhere we think we see it. Pet owners are particularly likely to identify feelings of guilt when their animals misbehave, but it turns out that while we're right to see guilt in the actions of small children, animals are a completely different story. In one study, 74% of dog owners thought their pets felt guilty after they misbehaved. However, a study by Alexandra Horowitz at Barnard found that the typical doggy "guilt" response - ears tucked, tail between the legs, skulking away and hiding - is not a reaction to breaking rules at all. In the study, some dogs were allowed to eat a forbidden treat while their owners were out of sight, while others had the treat removed, so they were forced to "obey". The owners then returned, and were told if their dogs had been obedient or disobedient in their absence. The catch: some owners were given the wrong information (that is, told that their dog had disobeyed and stolen the treat when they had not). The responses of the dogs showed that their behavior was in no way being driven by some internal moral compass; dogs that had obeyed were no different from dogs that had misbehaved. However, the reactions of the owners did influence their behavior: when the owners believed their dogs had disobeyed, the dogs looked guilty, when the owners thought the dogs were innocent, they behaved normally. In this case, the "guilty" look isn't a result of the dogs knowing they've done something wrong, but simply a sign of submission to an angry superior.

Does this mean that animals don't feel guilt? Like most traits that we try to pinpoint as uniquely human, the differences between our experience of guilt and that of nonhuman animals is probably quantitative, not qualitative. Other animals seem to have some sort of guilt-like emotion that influences their behavior, but it is more directly related to fear of punishment than the more psychologically based human counterpart. Looking at guilt in animals does give us an important clue to the evolutionary origins of the feeling, however. From the results in dogs, I would imagine that guilt might have emerged in some social ancestral species as a way of controlling individual behavior within a group. If an individual broke a rule, they were likely to be punished by dominant members of the group; those individuals who were able to anticipate that punishment and act submissive before it arrived were more likely to escape being hurt (and so, lived to pass on their genes to the next generation, etc.) This preemptive submission in the face of disapproval is basically what Horowitz identified in dogs; it's not too big a leap to imagine that as our brain developed more and more sophisticated cognitive machinery, including the ability to plan ahead farther in advance, we would begin to feel guilt even before the threat of punishment was looming. Eventually, the early submission (characterized by all the behaviors those toddlers showed - hidden face, averted gaze, hunched shoulders) would become completely divorced from punishment - transforming into the "guilt" we experience today.

The bottom line: the next time you're feeling that sinking feeling in your tummy, maybe it would help to ease your conscience to remember that what you're feeling has been programmed into your brain by thousands of years of natural selection to make you better able to live in a group. In other words, don't sweat it, it's just your genes taking over.

Russian street smarts

2009-09-01T10:05:00.000-07:00

Speaking of the intelligence of dogs, a friend recently brought to my attention the astonishing savvy and adaptability of Russian street dogs. Apparently Moscow has a large population of feral dogs, and the dramatic changes in their behavior could be seen as a perfect illustration of everything that has changed in Russian (human) society since the fall of communism. For one, as the city center has developed, the dogs have moved to the suburbs. However, many of them still commute in to "work" in the city everyday, riding the metro. By watching humans, they've figured out how to get on and off the metro cars. Like their human counterparts, they'll often nap during the ride, sometimes even missing their stop; if this happens, they'll get off, and reboard a train heading in the opposite direction. Overall, their use of public transportation shows and amazing degree of learning.

The learning doesn't stop there. Russian dogs have also adapted to the dangers of their new environment in other ways. They've learned to wait for cross walk signals to cross the street, for example, and have apparently figured out the best ways to get food in modern Moscow. These, reportedly, include begging (by endearing themselves to other train commuters, for example), and sneaking up behind people who are snacking on street food and barking suddenly. More often than not, the victim drops his treat, leaving it to the dog to gobble up. Pretty clever!

Again, it's meaningless to claim that one animal is smarter than another - all animals show different abilities, and comparing them to human cognitive abilities is pretty anthropocentric. So what I think is really amazing in this story is not the fact that these dogs have figured out how to behave like humans, or solve problems in a way that seems human like, but that they've been able to adapt to a complex and dangerous environment so quickly!

The rook and the water pitcher

2009-08-27T11:55:00.000-07:00

I talked about this study a few weeks ago, but today someone sent me a link to footage of the rooks actually solving the water-pitcher problem. To refresh your memory, the study was based on one of Aesop's fables, in which a crow dropped stones into a water pitcher until the water level was high enough for him to drink. Researchers found that rooks (a crow relative) actually are able to solve the task this way; in this case, the incentive was not just to get a drink of water, but to reach a small insect floating on top.

You can see the footage here:

Or, watch a longer version with multiple trials and all three test rooks at the Current Biology website.

I remember you...

2009-08-26T09:52:00.000-07:00

A few recent run-ins with old acquaintances have made me realize just how good we humans can be at recognizing each other. There are several aspects to recognition : we can spot a friend by their height and body type, say, or identify someone by the way they move; smell is even supposedly a significant recognition cue (although the effect mostly exists for blood family members). However, by far the most important way we recognize each other is by looking at faces. Facial memories tend to be very accurate and very strong - so much so that an old middle school friend was able to spot me on a crowded train the other day, in a city across the country from where we grew up.

As I've mentioned before, faces are so important to us that we've developed a special brain system for spotting them quickly. The selective pressure to be able to remember individuals also may have led to the enormous variability in human facial features. This theory goes something like this: as our ancestors were developing more complex societies, with more cooperation and other interactions, it became important to remember who was a friend or ally, and who was a mooch or an enemy. The reward of being recognizable in a system of reciprocal altruism is that you can get repaid for your past good deeds; thus, individuality might have been beneficial for those trying to get ahead in a social group (and, as natural selection goes, those who had the most variable facial genes got repaid most for their altruism and survived to reproduce more often, passing on more of those genes to the next generation). This theory makes intuitive sense to me, and is supported by looking at some other animals with highly complex societies. For example, our closest ape relatives, especially chimpanzees, also tend to have a lot of individual facial variation; it doesn't take a lot of training to be able to tell chimps apart. The most social animals in the world, eusocial insects like honeybees and ants, don't rely on facial recognition, but do have highly sensitive chemical mechanisms for recognizing each other. Same selective pressure, different solution.

However, if this is the full story, why aren't all social animals easy to identify? Why is it so hard for us to tell one prairie dog from another, for example? An NPR story refers to this mystery as "The crow paradox". A study published last year found that crows (a social animal) are able to recognize human faces. Apparently, crows can recognize the faces of researchers that have trapped them in the past, and will bear a grudge towards those individuals for years. However, as the NPR article points out, while crows can recognize us, it's awfully hard for us to tell them apart (just try playing this interactive game - it's almost impossible!)

If individual variability is an advantage for social animals, why don't crow faces look more different from each other? Is it possible that they are just as diverse as us, but we simply aren't used to differentiating them? It's possible, but seems unlikely - even researchers who devote their lives to studying crows need to tag them to tell individuals apart. A more likely possibility is simply that the selective advantages of being different weren't as strong for crows for some reason - perhaps because those genes were linked to negative side effects.

It's worth noting that even though we have trouble recognizing individual crows, they have no problem recognizing each other. So maybe, for whatever reason, they're just better at picking up on small facial visual cues than we are. Studies keep demonstrating that animals that look identical to us are able to recognize their friends and enemies through "facial" or other physical visual features. A recent study, for example, found that crayfish are able to identify individuals they've fought with in the past based on facial features like color and face width. Maybe, when it comes to face recognition, we just need to acknowledge that we humans are no match for the crayfish and the crows!

Smart as a dog?

2009-08-18T17:29:00.000-07:00

Thinking about the impressive intelligence of crows and the many human-like qualities of dogs, the obvious next question is, how do dogs stack up, in terms of intelligence? Everyone thinks his dog is a genius, but how smart are they really?

The question is more difficult to answer than it seems. Yes, dogs are intelligent, and are able to do some pretty complicated cognitive tasks. For example, in one study, where dogs were allowed to choose between two quantities of food, dogs were able to remember which was the larger portion of food, even when the choices were viewed successively. That means that the dogs were able to assess an option and compare it to their memory of the other option, then remember which was bigger - not bad, for a dog. Even more impressively, dogs, like human children, appear to be able to show "inferential selective imitation". This basically means that if a dog (or child) is shown a model performing a task in a way that is inefficient - using their head instead of their hand, for the humans, or their paw instead of their mouth to pull an object, in the case of the dogs - and they have no explanation for why the model is performing the task that way, they will imitate it. If, on the other hand, it is clear that the human model's hands are otherwise occupied, or the dog model is carrying something in its mouth, the child or dog subject will understand that the task is being performed inefficiently, and will not imitate the models' methods. But, again, if there is no other explanation for why they would do the action that way, the child or dog will assume that there must be some purpose they don't understand, and mimic them. This ability to trust in someone else's experience and greater wisdom is believed to be one of the necessary elements for culture to develop.

On the other hand, comparing intelligence among animals is a very relative things; in the end, we are comparing them to ourselves, asking how closely their minds resemble our own. But the definition of "intelligence" is vague. So in another sense, the question, "how smart are dogs?" (as compared to cats/apes/potbellied pigs) has no real answer. As one of my professors puts it, dogs are the smartest at being dogs, and cats are the smartest at being cats. Every species' brains and cognitive abilities, no less than their bodies, are shaped by natural selection. A dog looks the way it does because it is a carnivore; it has adapted special mental and physical abilities for living in a social group, hunting prey, etc. This is why dogs are fast and have a keen sense of smell and hearing, and also why they are so good at communicating. At the same time, their evolutionary history hasn't prepared them for solving certain kinds of cognitive challenges. The best example of this is from a study where a squirrel and dogs' spatial reasoning abilities were compared. In this classic study from the 1970s, a dog and a squirrel were both tied on a leash; the leash was wrapped around a post, and a bowl of food was placed just out of reach. The trick to reaching the food was simply to go back and unwrap the leash from around the middle pole, increasing its length and making the food easily accessible. Amazingly, while squirrels were quickly able to solve this spatial problem, dogs were not; the squirrel subjects got rewarded, while the dogs lunged at the food until they were exhausted than lay there, whining.

Why the difference in performance? This is the perfect example of dogs being smart at being dogs, and squirrels being smart at being squirrels. Although dogs show more complex cognition than squirrels on many tasks, the squirrels won at this one. This is probably because squirrels evolved in a three-dimensional environment, while dogs evolved on the ground, in 2-D. Thus, the selective pressure of having to leap from tree to tree gave squirrels a better ability to solve spatial problems. While the dogs were only able to think of linearly, trying to reach their goal (the food) by moving straight towards it, the squirrels were able to see that they had to loop backwards around the post to ultimately reach the food.

For more examples of dogs' lack of spatial reasoning skills, just check out Youtube:

But again, just because dogs haven't been selected to deal with three-dimensional problems doesn't mean we should write off their intelligence. While they may be bad at getting sticks through doors, they are also able to see aspects of the world that we humans can't. A prime example of this is the recent attention that's been given to cancer sniffing dogs. Apparently dogs can pick up on some subtle chemical cues and tell, with astounding accuracy, whether a person has cancer. Similarly, specially trained service dogs are able to tell when a person is about to have an epileptic seizure, or when a diabetic person's blood sugar levels get too low. So, before we get too cocky, comparing dog intelligence (unfavorably) to our own, we should remember that dogs are also capable of understanding and sensing things that are invisible to us; instead of comparing, we're better off just appreciating.

Some thoughts on man's best friend

2009-08-17T12:22:00.001-07:00

I've been spending some time in San Francisco's Haight Street neighborhood, the gathering place for street kids from around the country. Every corner has a posse of dreadlocked teenagers, begging for drug money and playing instruments badly. All of these kids have a few things in common: dirty ponchos, backpacks and sleeping bags; all under the age of 25; and, it seems, every group is accompanied by at least one dog - usually a pit bull mix. The dogs are obviously an important part of these peoples' lives - after all, taking on another mouth to feed when you have no income yourself is a tall order. So, why the glut of pit bulls? In this case, the answer is probably practical: cuddling with the dogs helps the kids keep warm on cold San Francisco nights, and an aggressive dog like a pit bull can be protection - an important consideration when you are living exposed and vulnerable. However, I'd guess there's more to the story here: these kids probably want dogs for the reasons that so many people do, friendship and devotion. The psychological benefits of having a pet - especially a dog, it seems - simply can't be underestimated.

The strength of our relationship with dogs is written all over the animal behavior literature. A ridiculous number of studies have looked at our best friends' behaviors, personalities, and genetics. This isn't unusual in itself - a handle of species get the privilege of being in the research spotlight, most notably rats, mice, zebra fish, C. elegans, fruit flies, and various monkeys (especially macaques). Dogs rank up there, as well, especially when it comes to behavioral studies. However, the reasons for using dogs are completely different than for using these other animals. Mice, fruit flies, and the like are chosen because they're easy and cheap to keep in a laboratory and breed quickly (and by convention, at this point). Non human primates are useful because they are our closest animal relatives, so conclusions from primate studies can plausibly be applied to humans, as well. But dogs? Dogs aren't particularly easy to keep in captivity, and are fairly long-lived. In fact, many dog studies use pets or shelter animals, not laboratory populations. The only reason for studying dogs appears to be that dogs are inherently interesting to us.

So, what have these various dog studies discovered? For one thing, dogs are more like us than we'd imagined (well, than some of us had imagined; they are probably less like us than some Leona Helmsley types would imagine, as well). As I've mentioned here before, dogs are remarkably good at communicating with us. It also turns out that they have similar personality traits to humans, like reactivity, fearfulness, sociability, and aggression. What's more, we may be able to pick up on those personality traits when choosing a pet; much as we choose compatible partners, people tend to choose pets that have similar personalities to their own (just read some of the testimonials on this slideshow of look-alike dogs and owners). We even choose pets that look like us - a recent study by researchers at UC San Diego found that test subjects were able to correctly match up an owner with their dog more often than expected by chance. And, while people choose a dog that is most like themselves, other research shows that dog owners are different, personality-wise, than other pet owners. For example, dog owners appear to be more outgoing and less intellectual/curious than horse owners; they also tend to rate their pets as being more "complex", "considerate", and "creative" than the horse's owners claim of their animals. While I'm not a huge fan of this kind of survey study, and I'm not sure what type of conclusions to draw from these results (the differences between means are small), it is fun to look at; for example, rabbit owners were the most neurotic people surveyed, and cat owners were the least agreeable. And apparently hedgehogs are the moodiest pet, while ferrets are the most imaginative.

Thinking crows and human animals

2009-08-12T09:13:00.000-07:00

I've always heard that crows are smart animals, but a couple of recent studies show just how smart they are. First, a group of researchers at Oxford found that crows are able to spontaneously use tools sequentially to get food. While crows using tools is nothing new - they've been known to make and use a variety of tools in the wild and in captivity - the tool use exhibited here was truly impressive. To reach the food item, the crows had to use sticks to reach for progressively longer sticks - that is, use tools on other tools, rather than simply using tools on the goal item. This type of tool use, called sequential tool use, or meta tool use, is considered to require more cognitive sophistication than more direct tool use; importantly, this type of behavior has rarely been observed in other animals. What's more, the crows solved the sequential tool problem spontaneously, without having the method demonstrated by the experimenters.

In a similar vein, another British research group, led by the appropriately named Christopher Bird, found that rooks (a crow relative) are also capable of complex problem solving. Bird and his colleague set out to test a scenario from Aesop's fables, in which a crow uses pebbles to raise the water level in a pitcher of water so that he can drink. They found that, given a glass of water with a floating insect just out of reach, rooks were able to spontaneously solve the problem in the way Aesop suggested, adding just enough pebbles to bring the insect into reach. The birds also learned to preferentially use large pebbles over small pebbles, showing an adaptation of methods as their understanding of the problem deepened.

All of this impressive bird cognition strikes down one of the few, shaky animal-human distinctions still remaining. The idea that some sort of concrete, unique human trait exists is slowly being erased as more and more behavioral evidence comes in to the contrary, but old habits die hard, and many find the disintegrating barrier disconcerting. Distinguishing ourselves sharply from the animal kingdom is an old Western intellectual tradition - as old as our monotheistic texts, which claim that man was created separately, to rule over other animals. Of course, Darwin knocked us down a notch from this top-ranking spot by explaining how humans and earthworms are actually cousins. But, objective as we pretend to be, scientists are rooted in their cultural traditions, and in the case of Western science, those roots fed directly in to the biblical teaching of human specialness. "We might share a common ancestor," scientists long insisted, "but we are still different." The essence of what makes us human was summarized in a list of differences, and the list became the definition of humanity, concrete evidence that we are NOT animals.

Unfortunately, as research has progressed, the list has shrunk alarmingly. One by one, traits that were once considered unique to Homo sapiens have been found in other creatures. Language? Culture? Individual personality? Consciousness? All present in animals. What's more, these abilities aren't even limited to our closest relatives, the great apes; scrub jays, dolphins, and octopi are all proving to be far more cognitively sophisticated than we had ever guessed. This complex tool use in corvids is merely another blow to our unfounded ideas of specialness amid a veritable assault.

I recently read a book by Charles Siebert called The Wauchula Woods Accord, which is a fascinating look at the human/animal connection - both the historic views, and the changing view today. Siebert points out that our relationship with animals has always been complicated. For example, he describes how animals were routinely put to formal trial in Western Europe for alleged "crimes" like assault or theft, and as recently as the early 20th century a dog was charged as an accomplice to manslaughter in such a trial. At the same time, we are all aware of how animals have exploited by humans in all sorts of horrific and cruel ways. Siebert comes across as strongly pro-animal rights (or at least, an advocate of other cognitively sophisticated mammals, especially chimpanzees, elephants, and whales), but he doesn't have any answers as to how exactly humans and animals should ideally coexist, and what, if anything, does distinguish us. Still, while answers may be hard to come by, these studies are just the most recent in a long stream of research that is forcing these questions into debate.

Redheads, foxes, and wives tales

2009-08-09T10:32:00.000-07:00

I just ran across this article in the NYT about individual differences in pain sensitivity, and it's even more bizarre than the effects I mentioned in my last post. Apparently, natural redheads are significantly more sensitive to pain than people with other hair colors. A study described in the article showed that redheads are more resistant to local anesthetics than blondes, brunettes, or black haired people, and that they consequently report more pain during dental procedures and are more afraid of going to the dentist than other people. The study linked the sensitivity to a gene mutation that also affects pigmentation of the hair and skin; cells produce pheomelanin instead of melanin, resulting in red hair and pale skin, but melanin is also related to pain receptors in the brain.

This study illustrates a number of really interesting scientific ideas. First, it shows, yet again, how powerful individual differences can be. A lot of science has to do with generalizing, with finding rules that summarize and group (i.e., "pain works this way"...). This is useful, and necessary for broadly understanding the world, but not always that accurate (especially for psychology and behavior). Sometimes the individual differences are the most interesting part of a phenomenon - for example, the fact that so many aspects of biology, culture, and social context can effect how we perceive pain.

Another fascinating aspect of this study is the example of the multiple effects of single genes. Perhaps because of the mental appeal of simplifying things, or perhaps to make science better fit into a media headline, we too often refer to genes as being "for" a certain trait. Scientists will discover a gene "for" obesity or breast cancer or depression or risk taking or red hair. However, this is an inaccurate way of looking at genetics, and leads to some major misunderstandings about the way genes work. It's very rare for a single gene to cause a trait; more often, any given trait is the result of the effects of multiple genes and environmental influences. Even when a trait can be pinpointed to a single gene, as with red hair, that gene can't accurately be called the gene "for" red headedness, as all genes have multiple effects. As this study showed, it would be just as accurate to call it the gene "for" increased pain sensitivity!

My favorite example of the unexpected multiple effects of single genes comes from a long term study of silver fox domestication in Russia. The project began about 50 years ago, when a number of wild foxes were caught and brought to the research facility. They were kept in large outdoor pens, and did not interact with humans except during a daily feeding. The experiment was simple: every generation, the tamest foxes were chosen to breed - that is, the foxes who seemed least afraid of their human feeders, who were least likely to run away or bite them. In this way, the researchers were simply putting a selective pressure on a single trait, tameness. However, amazingly they found that over the course of a few generations, the foxes not only became extremely tame, they also developed an array of unexpected physical characteristics: they're ears became droopier, their tails curlier, their fur had white spots. In short, they developed a lot of the physical characteristics that we see in other domestic animals (dogs, cats, mice, pigs, cows - even tame pigeons!), demonstrating that these physical traits must somehow be influenced by the genes that affect tameness!

The last aspect that I liked about this study was that the researchers in this case were willing to look for validity in something that had been considered an old wives tale. Apparently dentists had long claimed that red heads need more anesthetic than other patients, but the idea was dismissed as a trade myth until this study proved it correct. Of course, not all collective wisdom is true, but I appreciate it when science at least takes seriously knowledge gained from other methods (that is, not scientifically established); while they may not always pan out, legends and folk wisdom can sometimes be the basis for useful and interesting findings such as this.

Pain killers

2009-08-05T15:21:00.001-07:00

I'm an active person, and try to run or do yoga everyday. Usually this is a way of releasing stress, of calming myself; however, in the past week, my exercise habit has totally backfired on me, causing me more harm than good. During last week's heat wave, I managed to give myself mild heatstroke twice (symptoms: extreme nausea, fatigue, and dizziness) by not drinking enough water before long runs. And yesterday, less than a mile into my run I tripped and slid across the pavement, tearing up my knees and hands. I take this little spurt of injuries as a message to my brain from my body - a plea from the grunt laborers of the muscles and joints that central control needs to slow things down a little. The fact that I can run myself well into dehydration without knowing, that I can force myself to go for a run when my body is too tired (what I blame the tripping incident on; this happened on a flattish stretch of sidewalk), seems to indicate a gaping disconnect between my mind and my body. What's more, I noticed yesterday that the fall stopped me cold; I was pretty messed up and in pain, and I ended up trudging home. In contrast, last year I ran the SF marathon, and had a similar incident around mile 6 or 7. In that case, I hopped back up from my fall, legs bleeding, and ran another 20 miles. Only later did I realize I'd sprained my elbow - at the time, I felt almost no pain. Why the different responses?

A glance at the literature on pain and exercise shows that my experiences are not unique. Exercise can literally change the chemical make up of your brain, altering your perceptions of the world. And one of the most well-studied effects of that chemical influence is the pain-numbing effects of exercise. In a number of studies, physical activity results in an increase in pain threshold - that is, after exercising vigorously, people appear to be less sensitive to pain. Moreover, several studies show evidence that athletes, or people who exercise regularly, have higher threshold levels to pain. Even when they haven't just been working out, their pain tolerance is higher than the average sedentary person's. At least one study has even demonstrated that runners, in particular, are resistant to pain (or, in the words of the article, "stoical") even when compared to active non-runners. Together, these studies explain why I can usually be fairly tough when I'm running, but much less tough/stoical when I'm just starting a run.

Of course, exercise is not the only factor that effects pain perception. Biology plays a role in determining how much pain we feel, as well. In particular, men and women experience pain very differently. In humans, women are more likely to visit physicians and are more likely to report pain as a symptom than men. They also generally describe greater levels of pain. While this trend could be due to cultural norms - men are often expected to be tougher than women - the same pattern has been seen in rodent studies. In general, female lab rats have lower pain thresholds and larger responses to painful stimuli than male rats. Interestingly, while women tend to be more sensitive to pain than men, they also show an larger pain-numbing effect from exercise. This sex difference is further complicated by women's hormonal changes throughout the month; normally menstruating women appear to have increased pain threshold levels as their hormones change. In contrast, men and women on oral contraceptives don't show threshold differences over time.

While the chemical make up of our bodies influences how we experience pain, psychology and cultural expectations play an equally large role. One study, for example, showed that South Asian men showed lower heat pain thresholds and reported higher pain levels than white British men. The proposed explanation for the difference between the groups was cultural norms; the South Asian men were more comfortable expressing pain. Reports of pain levels are also influenced by who does the pain testing. Men apparently report higher pain thresholds when they are being tested by women than by men. Interestingly, women aren't influenced by the tester's gender. It seems like this could be a cultural effect; because men are expected to be more resistant to pain, they show this effect more strongly when they are trying to impress a prospective mate (a woman tester). It would be interesting to see if the same effect would show up if a man was tested by a male researcher, but with a woman present in the room. Men also might be expected to show even larger increases in pain thresholds if they were competing with another man (that is, if they were both being tested at the same time, especially by a woman tester).

It also turns out that all of those Mighty Ducks type sports movies were right all along: if you believe in yourself, you really will perform better. At the very least, you'll feel less pain. A series of studies have shown that self-efficacy - basically, the belief in your own abilities - correlates strongly with decreased pain during exercise and other pain tests.

Finally, if all else fails, it seems that letting out a stream of expletives might just help. A recent study shows that swearing - a natural response to painful stimuli for many people - actually does increase pain tolerance. The researchers aren't quite sure why that reaction might occur, but suggest that swearing induces a fight-or-flight response, setting off a stream of hormones that overrides fear of pain and dampens the nervous system's sensitivity. I'll keep that in mind next time I trip over my own feet...

How we get lost

2009-07-27T14:47:00.000-07:00

The last post about wayfinding got me thinking about the flip side of how we find our way: how we get lost. While some researchers focus on the strategies we use to navigate, a smaller and distinct group of research looks at how we can get disoriented - and what the psychological effects of disorienting spaces might be.

Who hasn't had the experience of wandering around a large hotel or hospital, trying to find a specific room, but being confused by hall after identical hall? As I mentioned last time, the two key strategies for wayfinding depend on identifying landmarks or gaining a sense of the overall spatial relationship between locations - both of which are difficult in these spaces. The fact that these buildings often require maneuvering through twisting passages and over multiple levels makes it hard to keep track of what cardinal direction you are moving in, making the structure spatially confusing from the inside . On top of that, the only "landmarks" tend to be bland, nondescript artwork, and the homogenous lighting, carpeting, or wall coverings are not helpful as directional cues. The most maze-like of these structures are the ones without windows - at least in those cases, exterior cues, like the direction of the sunlight, can give hint at where you are. However, these features are inherently at odds with the goals of these buildings (to be as efficient and neutral as possible), and so large, industrial buildings tend to be one of the best places to get lost.

Another good place to get lost is in a casino or shopping mall. Like hotels and hospitals, these buildings are built for efficiency, meant to accommodate a large number of people at a time, but there is another possible motive in the design of these spaces: to keep people inside for as long as possible. S ome speculate that architects for these buildings purposefully make them as disorienting as possible, with the theory that the longer people spend inside, the more likely they are to spend money (If you don't believe this, just visit an Ikea store - the layout makes it very difficult to get out without first winding your way through a display of all of the company's products. From my experience, this makes it a lot more likely that you'll decide to buy a ladle or some picture frames that you don't really need than if you could navigate more purposefully). As in the hotels and hospitals, part of the problem here is a lack of natural lighting and differentiated spaces - all of the hallways tend to connect or twist into each other in these places, making it hard to say where one space ends and another begins. Even more disorienting, though, is the visual clutter; unlike the monotony of a hotel hallway, a casino overwhelms you with too many landmarks. With lights, color, and movement all around, it becomes (paradoxically) impossible to fix on any one object as a landmark.

The question is, how do these spaces effect us? Personally, I tend to get overwhelmed and panicked, and want to get out as quickly as possible, but I doubt that's the effect the designers are going for. One suggestion is that in these confusing spaces, we simply give up our self control, becoming directionless, wandering slowly, and going with the flow. In this scenario, the layout of a mall actually changes our behavior, making us into aimless zombie shoppers - more likely to buy things on impulse than to search for a specific item.

Overall, environmental psychologists (that is, scientists who study how a spatial environment effects the mental state and behavior of the people in it) agree that we feel most comfortable in structures where there is a stable, clear spatial relationship to our surroundi ngs. Without that clarity, we can lose our sense of control or purpose in the environment. On top of that, extreme disorientation can lead to even more negative mental health effects.

Take, for example, the case of the Lindemann Mental Health Center in Boston. apparently, the building was designed by architect Paul Rudolph, who took the whole "madness" idea not as the purpose of the building, but as its theme. According to an article in Metropolis Magazine, the building is full of twists and turns and stairways that disorient the patients (and doctors), further adding to their mental health issues. A few especially whimsical/sadistic details that Mr. Rudolph added were a catwalk that had to be roped off because patients kept jumping from it and a host of nooks and crannies where patients can hide and leap out at unsuspecting passersby. The front of the building forms a strange, gargoyle-like face – yet another example of our tendency to see faces in inanimate objects, but in this case a little more disturbing (I wouldn't expect that it's particularly comforting to patients already prone to hallucinations, for example).

"Gargoyle" on the Lindemann Mental Health Center

Another of my favorite disorienting structures is the Winchester Mystery House, a popular tourist spot in San Jose, CA. Strange and conflicting stories surround the building: that the widowed Mrs. Winchester was trying to escape demons (literal, not figurative) that were chasing her, that she was instructed by a soothsayer to never stop adding to her house (to appease the dead, or something), and that the building is haunted by the ghosts of all the Winchester family. While an article on the house in the Skeptical Inquirer suggests that some of its more bizarre features - hallways that dead end, stairs and doors that lead to nowhere, and an insanely long, winding staircase, among others - can be explained away more rationally, being in the space is still hugely disorienting and eerie (I've taken the tour). Whether or not any of the legends are true, the space just feels wrong - evidence that, if nothing else, Mrs. Winchester must have had some mental health issues of her own. And the whole Winchester mystery house phenomenon seems to indicate that anyone inside a space that disorienting starts to feel nervous and confused - perhaps explaining all of the "ghost" sightings that have been reported in the building.

How we find our way

2009-07-22T22:40:00.000-07:00

I consider myself someone with a decent sense of direction - certainly not exceptional, but not hopeless, either. I get lost frequently, especially when I go running, but even when I have no idea which road will lead me home, I can sense the general direction. However, there are some places where I find myself hopelessly lost, like unfamiliar college campuses (all the buildings look the same!), or the parts of Seattle where the streets abruptly dead end, resurfacing a few blocks later. In fact, this last can be such a problem that there are a few spots in the city I can only get to by following a route I've taken before. There's probably a faster way to get to Ballard from Capitol Hill than my path, but whenever I make the trip, I retrace my old steps.

Apparently, this is not all that uncommon a strategy for finding your way. Researchers who study orientation and navigation identify two major categories of wayfinding (that's jargon for "finding your way"): route and survey strategies. A route strategy is what I use to find my way to Ballard - following a known path from point A to point B, perhaps relying on landmarks on the way. Survey strategies, on the other hand, show a more sophisticated knowledge of a space, a true understanding of how a starting point and a destination are geographically related. If I had a survey knowledge of the relationship between Capitol Hill and Ballard, I would be able to take a number of different paths, to zigzag through Fremont and Phinney Ridge effortlessly and still reach my destination. Apparently, though, most people tend to favor one strategy over the other; I am afraid that when it comes to driving, I tend to rely primarily on route knowledge.

Several studies show that women rely more heavily on route strategies to find their way, while men are more inclined to use survey strategies. This finding can also be interpreted as evidence that males are more adept at spatial reasoning in general (although this is a dicey topic, as proclaiming that men have superior spatial abilities leads to the claim that men are also superior in fields that demand spatial reasoning - like complex mathematics and physics; whether or not this is true, saying it loudly is definitely a dangerous move - just look at what happened to Lawrence Summers!) This sex difference in spatial reasoning and navigation pops up time and again in studies, and so, inevitably, evolutionary psychologists have taken interest.

One interesting, if kooky, explanation for this difference between men and women is that it stems from the demands placed on our hunter-gatherer ancestors. According to this theory, our ancestors had a pretty rigid division of labor: men were hunters, women were gatherers. Perhaps, in this dichotomous society, using survey strategies was helpful for chasing down prey over complicated and unpredictable landscapes, while gathering called for a route strategy, where women gatherers would wander from one landmark to the next (say, from a berry bush to a walnut tree). For the hunters, understanding the spatial connectivity of the environment was crucial, as they had to keep from getting lost while running around erratically; for the gatherers, following a known trail was most valuable, so they specialized in that strategy. It sounds like a stretch to me, but in a (bizarre) experiment, researchers found that when food was involved (specifically, fruits and vegetables at a farmer's market), women were more accurate than men at understanding the spatial relationship between food sources.

In most studies, researchers assume that for both route and survey strategies people are relying mostly on visual information to find their way around (we are primarily visual animals, after all). However, this certainly isn't the only way to get around - in fact, when you're traveling long distances, it appears to be a pretty inefficient way to figure out where you are. The serious travelers - migratory animals, like birds or sea turtles - rely on the earth's electromagnetic fields to find their way. The same is true for many deep sea creatures, like lobsters, who don't have a lot of visual information to go on. Over the years, a number of scientists have suggested that humans are also capable of tapping into this information source, even if we are not usually aware of sensing it. In a series of experiments in the 1970s, the British scientist Robin Baker tested this idea by blindfolding subjects, driving them on a long, circuitous route out to the woods, then asking them to point the direction home. In his studies, humans were surprisingly successful at identifying the right direction; Baker attributed this success to the subjects' perception of magnetic fields. However, pretty much every attempted replication of the study has failed to find the same result. Still, it's not impossible that Baker was on to something: more recent studies have found that the human brain does respond to weak electromagnetic fields. If we are able to perceive them, then perhaps we are capable of using them for navigation, just like pigeons and turtles.

Talking with animals

2009-07-21T10:29:00.000-07:00

Watch a pet owner interact with their dog or cat for a few minutes, and you'll immediately notice how much they talk to their animals - often as much as they would to another person. But one of the questions I get most often when I tell people I study animal behavior is, "how much does my dog/cat/ferret/parrot understand?" We humans are such social creatures that it's hard for us NOT to talk to animals; however, we are still uncertain whether or not we are actually communicating anything. Are we talking to intelligent beings, or furry throw pillows? Many pet owners insist that Fluffy has an enormous vocabulary, or that Fifi knows when they're talking about her, but how can scientists test this?

Tests of vocabulary seem like the most direct way to get at how much animals understand, but they pose some problems. True, recognizing a word means that an animal has come to associate that sound with a given object or activity, but does that really mean they have an understanding of abstract representation? Most animal languages that have been studied seem to be more associational than representational (with the notable exception of the language of honey bees). For example, vervet monkeys have one of the most extensive vocabularies known, with distinct alarm calls to specify exactly what type of predators are present. If a monkey makes the eagle call, the other monkeys in the group will dive under bushes; if he makes the snake call, they will climb a tree. The calls are obviously different, even to the human ear, and the animals respond to them with appropriate reactions that indicate the call carries a meaning. But one could interpret this "understanding" of the calls as mere association - a fixed behavior triggered by a specific sound. An old-school ethologist would explain the monkeys' reactions entirely in terms of fixed action patterns, or instinct, rather than understanding.

This often leads to a frustrating dead end - is it language or instinct? Comprehension or association? Still, some examples have indicated that animals do have a fairly deep understanding of language. Dogs have been shown to have extensive vocabularies and impressive deductive reasoning skills. One border collie named Rico, for example, has been demonstrated to know the names of more than 200 objects. His vocabulary was tested by having him fetch objects; when scientists asked for a ball, he would bring the ball, and so on. What's more, in tests, if Rico was told to fetch a "gidget" (some word he did not recognize), he was able to do so correctly, bringing back an unfamiliar object. Parrots and chimpanzees have also performed well on similar tasks.

Beyond vocabulary, scientists are also interested in how much animals understand - that is, how much they can identify the intentions of the communicator. One aspect of understanding that is particularly measurable is gaze-following. It may seem painfully obvious to us humans that a prolonged gaze or a pointing hand is a signal to "look over there!", but the truth is that understanding these gestures requires a lot of cognitive sophistication on the part of the recipient. For one thing, it requires some aspect of theory of mind, an understanding of the pointer as an intentional being. That is, to know that a pointing finger in the air means "look over there", you have to know that the guy who's pointing might have some information that you don't have and that he's trying to share it with you. Then you have to figure out that the direction of his point corresponds to the direction of the information, from his perspective; you have to orient yourself the same direction as he is to "follow the point" - so even if you understand the concept of the communication, you have to know to follow from the finger, not, say, the shoulder, or perpendicular to the elbow. When you think about the number of cognitive processing steps involved, it's pretty impressive that so many animals can understand this communication.

For some animals, it's not too surprising. Domestic dogs, for example, have evolved with us for thousands of years; the fact that they can understand human facial communication isn't too shocking. Still, it's worth noting that studies have shown that dogs are just as sophisticated as fanatical pet lovers would have you believe. Not only can they follow pointing and gazes, but they know that humans communicate mostly with their eyes and faces; thus, they know to bring a toy to the face-side of a person when playing fetch, and to beg for food from someone with visible eyes (as opposed to someone who is blindfolded). They can also follow a point or gaze around a visual barrier (that is, even if they can't see the object of the point, they know how to look for it).

Other cognitively sophisticated, social animals, like nonhuman primates and dolphins can perform gaze following tasks as well. Moreover, African gray parrots can spontaneously follow pointing gestures, and can learn to follow sustained eye gazes, and ravens turn out to be particularly good at these tasks, capable of following a gaze around a visual barrier. All together, this means that many types of animals understand the concept of communication and can learn to pick up on human signals.

However, there is a lot of work to be done, and it can be slow going... the scientific community is slow to accept claims of animal understanding, skeptical of anthropomorphism. While this is a valid concern, it can make progress in the field slow going. For example, the New York Times Magazine recently published an interesting article about human-whale interactions. In particular, the article mentioned some mysterious whale behavior in an area of Baja California. Apparently, the region is a breeding ground for gray whales, and in recent years, the whale mothers have become increasingly friendly with local fishermen, seeking out their company and "introducing" their babies to the boats. No one is sure what could be triggering this behavior, besides some vague desire for social contact. Most of the explanations offered seem anthropomorphic by traditional scientific standards, but the scientists studying the phenomenon seem to feel that the traditional language of ethology, which explains behavior by instincts and stimuli, is insufficient to describe what's going on here. Although chipping away at the question with our reductionist science makes it hard to answer definitely how much animals understand, it seems like eventually we're going to have to concede that it's more than we ever thought.

Rules for a digital world

2009-07-14T08:03:00.000-07:00

As technology becomes more powerful, more and more of our social interactions are taking place digitally. This is hardly a new observation, and the media has been wringing its collective hands over the possible implications of this shift for years now. Will we lose the ability to connect to others in real life? Will we become more aggressive, more blunt, and with shorter attention spans? Will we lose our senses of privacy, over-sharing with the world? These pessimistic prophecies go on and on; the one point where they agree is that socializing virtually is going to somehow damage human social interactions.

Enough has been said about the negatives of virtual sociality that I don't feel the need to put my two-cents in now (maybe someday I'll feel more ambitious). What I do want to mention is a study I ran across recently that showed the flip-side of this topic: how our real-life social norms affect our behavior in virtual reality. The project was an observational study of how people interact in Second Life, the massive virtual world where participants interact with their environments and each other via avatars (animated characters that they choose or design). The study looked at whether avatar social interactions followed the same rules as face-to-face human interactions. In particular, the researchers studied interpersonal space - how close people stand when they interact. As we all know from experience, having someone stand just a little too close or too far away while chatting can completely change the tone of the conversation, making you feel uncomfortable or disengaged. It turns out that the appropriate interpersonal distance for an exchange depends on a number of factors: obviously the relationship between the two speakers, but also their culture and gender. In general, women tend to stand closer together when talking, and two men will stand farthest apart; a mixed-sex exchange will have a standing distance somewhere in the middle. It's also true that when we are forced into an interpersonal distance that is inappropriate for the relationship we have with a given person (say standing in a tight elevator with a stranger), we avert our gazes to "make up for" the standing distance. It turns out that all of these patterns (distances depending on gender of both parties in an interaction, averting eyes when standing too close) also persist in second life.

It may seem silly to think about a team of scientists skulking about a virtual world measuring the distance between virtual "people" (nerds studying nerds, you might say). But I do think it's interesting that these "rules" apply in Second Life, just as in real life. After all, this is an environment where you can do whatever you want - you're unbounded by the rules of reality. Avatars usually travel from place to place by flying, and many users choose to create bizarre or whimsical characters to represent them (a large portion choose to be giant, talking animals, for example). And, of course, the usual clues that someone is standing too close - hearing their breath, feeling their body heat, bumping into them - are absent in virtual reality. So why does this pattern continue, even when there's no longer a physical reason interpersonal space should make us uncomfortable? It's hard to say exactly why this should be, but it does support two ideas: first, that this is a deeply engrained social rule, and second, that virtual socialization isn't erasing every social norm as rampantly as critics had feared!

Written in the stars?

2009-07-09T14:04:00.000-07:00

As a scientist, I am sometimes embarrassed by my own irrationality. I've always had a fascination with the paranormal - ghost stories, psychics, tarot, and the like - that doesn't mesh well with my scientific worldview. Not that I believe in all of these things, necessarily - I just find myself much more open minded towards them than many of my scientist peers, who dismiss them off the bat. So far, my acceptance has only been a positive for me - I've been able to listen to and befriend people with a wide range of viewpoints, and learn something about their ideas. But recently I've been wondering - what (besides dismissal) does science have to say about these ideas?

A recent trip to San Francisco brought about a lot of astrology talk, so I decided to make this the focus of my investigation. I like to read my horoscope in the paper as much as the next person, and I know plenty of the supposed trait characteristics of various signs; I wanted to know whether there is any scientific legitimacy behind these habits, or whether they're just superstitions, like tapping my roof when I speed through a yellow light.

My first search of the literature on astrology revealed a couple of things: scientists (especially psychologists) have spent a surprising amount of time thinking about astrology, and some of them are pretty indignant about it. The views of some of these scientists are self-evident from the titles of their articles or letters on the topic: "No to Astrology" (in Nature, 1983), "Top Scientists Must Fight Astrology, or All of Us will Face the Consequences" (in Scientist, 1989), "Astrology or Arrant Trash" (in Current Science, 2001), "Belief in astrology - A symptom of maladjustment" (in Personality and Individual Differences, 1983) and, most ominous of all, "Astrology can damage your life" (in New Scientist, 1984). Unfortunately I couldn't track down that last one to find out exactly how astrology might damage my life, but it made me wary nonetheless.

Despite the threat implied, I decided to take a look at some actual scientific tests of astrology. How has it stood up in predicting the future or describing personality? For the most part, not very well. It appears that the skeptics have a point: astrology doesn't seem to be statistically correlated with any of the measures that have been tested so far - not that the researchers haven't tried. One study found no connection between horoscope sign and course of study in university (in The Journal of Social Psychology, 1980); another found that sign also did not predict personality or general intelligence in a sample of more than 15,000 participants (in Personality and Individual Differences, 2006) . In a somewhat mean-spirited test, a large sample of astrologers (51) were each given a group of birth charts, some of which belonged to bright children, and some to mentally retarded children; the astrologers were slightly worse than chance at identifying which child was which based on their horoscopes (in Current Science, 2009).

However, not all of the study results are so dismissive - some of them are merely ambiguous. In a 1999 article in the New Scientist, Jens Thomas describes some of the less-than-overwhelming evidence for astrology out there, including results that show that certain signs tend to be taller, or better bowlers, or more likely to get fat later in life, or more susceptible to revolutionary thinking. One champion of a real connection between astrological sign and personality was the late Hans Eysenck, who found connections between different signs and personality traits like extroversion/introversion. Not surprisingly, in a field so negatively inclined toward the idea of astrology, many of Eysenck's results were carefully scrutinized and replicated, and only some of them survived the re-testing. Still, it is interesting that despite the attention, some of his results still hold up. For example, a 1994 study published in Personality and Individual Differences confirmed that positive (odd-numbered) sun signs tend to be more extroverted than negative (even-numbered) signs. However, the researchers note that this is a self-reporting test, and the result may be due not to the control of the stars, but to the influence of astrology on the subjects' senses of their own identity.

Despite the lack of convincing evidence, the belief in astrology remains surprisingly strong across the board. As odd-numbered sun signs tend to be more favorable than even-numbered signs, some scientists have predicted that those with the favorable signs might show a stronger belief in astrology than those with unfavorable signs. However, the evidence on this is mixed; one study found the effect, while a follow up found that all participants believed in astrology equally (both in Personality and Individual Differences, 2001 and 2003). Why should this belief persist, when there is so little evidence to back it?

One explanation is what is known is psychology as the Barnum effect (after P.T. Barnum, who famously claimed that his circus had "something for everyone"). Basically, this is the tendency of people to think vague personality profiles are highly accurate in describing them if they are told that the profiles are specifically tailored to their personalities. This turns out to be especially true if the profiles contain more positive than negative traits. The Barnum effect is strong even among astrology skeptics; the same effect occurs when people are given false psychological personality profiles, as well. In these studies, the profile is supposedly tailored to the recipient using scientific principles, rather than messages from the stars, but the resulting profile is just as vague as any horoscope. However, despite the fact that these descriptions could apply to a lot of people, the recipient tends to think they are highly accurate at describing their own personality.

While everyone appears to be vulnerable to Barnum effects, researchers are quick to point out that some people are more susceptible than others. A few studies, for example, have indicated that women often show larger Barnum effects than men; not surprisingly, women also appear to be more likely to read their horoscopes than men (in The Journal of Psyschology, 1983). Some research has indicated that people with certain mental disorders are more susceptible to the Barnum effect or believing in astrology than average. One study showed that subjects who scored high on certain scales of psychotic characteristics also scored high on Barnum susceptibility, while another study linked belief in astrology and other paranormal phenomena to ADHD and depression (in the Journal of Psychology, 2006).

So, what to make of all of this? Is astrology nothing but bunk, a result of the Barnum effect, with absolutely no real world predictive power? Maybe, maybe not... as with many beliefs, astrology might be appealing not because of its high accuracy or usefulness, but as a way of understanding and categorizing the world. It gives us a way to categorize the people around us (i.e., "well, she's a leo, so of course she can get bossy and overbearing like that"). Whether or not everyone fits their proscribed category, the definitions are vague enough that most people will bear at least some resemblance to the description of their sign. The question comes down to whether or not this is an acceptable way to understand the world and explain people's behaviors. Despite the fact that a stricter rationalist might claim "astrology can damage your life", I can't see why not it's not ok to categorize people this way, especially considering there is (very, very slight) evidence that birth date might affect some traits and abilities. But then again, we aquarians do tend to be more open-minded, independent thinkers than some; that researcher was probably a Virgo!

Evolution, culture, and attraction

2009-07-07T13:34:00.000-07:00

This is a broad topic, but an article in today's science section of the NY Times made me at least want to touch on it. The article describes a recent study which casts doubt on the usual evolutionary wisdom that women are choosier than men in picking mates. In most animal species, females tend to be more selective than males in who they will deign to mate with; this process, called sexual selection, is the explanation given for elaborate male traits, like a peacock's tail. Because females provide a bigger investment in reproduction than males (that is, eggs are more energetically expensive than sperm, and often females provide additional energetic supplies, or postnatal care), they should be more careful about not "wasting" that investment on a sub-par male. The trend seems to explain a lot of strange male traits, and, in a perfect example of the exception proving the rule, males tend to be the choosier sex in species where there is a substantial male investment. For example, in the mormon cricket, males provide a big package of nutrition to the female along with the sperm; consequently, they are far more selective in choosing a mate than most male insects.

Most biologists have applied these same basic "rules" to explain human mating tendencies. In general, females do tend to be pickier than men in who they will partner with. But this study, by two researchers from Northwestern, suggests that sexual selection as we usually think of it may not be the main force behind womens' choosiness. The study used a "speed dating" set-up, and had both male and female participants approach potential partners. They found that whoever was the instigator in the approach was less "selective" - that is, they were more likely to think the potential partner was interesting/attractive enough to ask on a second date. The approachers reported greater desire for and more chemistry with their dates than those who were approached, regardless of gender. This implies that perhaps part of women's choosiness in humans is not driven by the evolutionary dilemma of where to best place limited reproductive resources, but rather, is cultural. Because men are socially often the ones to "make the first move", they are placed in the position of the "approacher" from the experiment, feeling attracted to and interested in those that they pursue. Women, on the other hand, are often in the social position of being approached; because of this, they may feel like they have more options, and as a result be choosier in picking a mate.

So the question is, do the results of this study mean that evolutionary theory doesn't apply here? I've heard this suggested before (mostly by non-biologists, for what it's worth) - that evolution doesn't explain human behavior anymore, that we're "beyond evolution". This seems absurd to me; like any animal, we have an evolutionary history, and that history influences our behavior. However, it's important that we take notice of studies like this, because it's too easy to fall into the trap of over-explaining, of deciding that every human behavior is purely a result of selection. Sometimes there are spandrels, side-effects of other traits that have been selected for (but which are no less engrained in our DNA), and sometimes there are behaviors that are not completely related to biology, as is apparently true of mate choice. Plenty of past studies have shown that many elements of who we are attracted to are consistent with an natural selection - for example, the fact that we tend to find symmetrical faces and facial neoteny beautiful (especially in women), or the fact that women are most attracted to the body odor of men who have a compatible immune system (for producing optimally fit babies). Obviously, we are not "beyond evolution" in these cases - selective factors from our evolutionary pasts are still exhibiting a hold on us. What we need to keep in mind is that not everything comes down to evolution - cultural and psychological factors are important as well, as this study indicates. It's important to keep all of these ideas in mind when looking at human behavior. As the research twists and turns, the one thing we learn for sure is that Homo sapiens is perhaps the most difficult and complex creature to study of all.

Real art history

2009-06-24T18:08:00.000-07:00

New findings, reported in the latest issue of Nature, give a fascinating insight into the history of art. A team of archaeologists headed by Nicholas Conrad have discovered flutes in a cave in southwestern Germany that date back to the last ice age - more than 35,000 years. The fairly sophisticated instruments are made of bone, and appear to be comparable to modern flutes in the sounds they produced, according to a New York Times write up. While it's amazing enough that our ancestors were creating music so long ago, the findings are even more impressive in light of some other artifacts that have been found in these caves. Earlier this year, Dr. Conrad

unearthed a sculpture of a female figure in the same cave system , possibly the earliest example of figurative art in the world.

While I have speculated on the possible evolutionary explanations for music on this blog before, perhaps these findings, and the discovery that visual art and music emerged at about the same time, add to that story. Did our ancestors create sculptures for the same reasons they created music? Could the emergence of art at this time mark a turning-point in the evolution of the human brain? For the most part, research on the understanding of visual art and music have followed parallel, but separate paths. Not surprisingly, scientists who study visual art tend to be concerned with vision, while researchers attack music from an auditory angle. But perhaps the simultaneous beginnings of these two art forms implies that we should be looking for a common cause.

Summer solstice

2009-06-22T07:42:00.000-07:00

Yesterday was the longest day of the year here in the northern hemisphere. In honor of the occasion, some friends and I (briefly) took part in a pagan celebration on the beaches on San Francisco. Our fellow revelers built a huge fire, sang songs as the sun set, and burned herbs, performing a ritual that has persisted for thousands of years. Indeed, some archaeologists believe that Stonehenge was built partially as a site for celebrating the solstice, more than 4000 years ago. The obvious question to me is, why? Why has this tradition persisted for so long, and why would ancient people celebrate the summer solstice at all?

Of course, the answers to these questions are hard to pinpoint. We can't go back in time to ask the original druids why they decided to celebrate the solstice, and if we asked people today why they celebrate the solstice, they would most likely say something about keeping traditions alive or feeling in touch with the earth and changing seasons. However, some research about the effects of seasonality on mood and behavior suggest one answer to me for why people might want to celebrate the longest day with fires, singing, and dancing: perhaps we are just happier at the time of the solstice!

Scientists have long found that mood changes seasonally - in particular, it seems to be related to sun exposure. Not too surprisingly, we tend to be happier when we see more of the sun. One 1997 study by A. Preti found that Italians showed a peak of suicidal behavior in the spring, the period when they had gone longest without sun and when rainfall was highest. Less severe than suicide, numerous studies have identified decreased winter sun exposure as the mechanism behind seasonal affective disorder (SAD). Interestingly, some people seem to be particularly sensitive to changes in sunlight; a study by Guillemete et.al. (1998) found that subjects who suffered from SAD didn't necessarily receive less exposure to bright light than those who were unaffected by the seasonal changes. Apparently, lack of sunlight affects some people dramatically, while others remain fully functional. The reasons for this difference are not completely clear, although it probably has something to do with individual serotonin synthesis. Serotonin, a neurotransmitter that seems to be related to mood regulation, is also implicated in other types of depression. Seasonal studies of serotonin production have found that production is lowest in winter, and increases with sunlight.

Taken together, these studies seem to suggest that we humans tend to feel happiest and most exuberant in the middle of the summer; the day of the longest sun exposure (summer solstice) should also be the day we synthesize the most serotonin and thus feel the most light-hearted. To oversimplify, then, perhaps summer solstice is such a joyful celebration, and has been celebrated for so long, because this really is the happiest day of the year!

The appeal of angry cars

2009-06-16T12:58:00.000-07:00

Time to acknowledge some interesting research from a group that shares the name of this blog, the Ludwig Boltzmann Institute for Urban Ethology in Austria. These guys are more focused than I am, using a narrower definition of "urban" and focusing strictly on observable human behaviors. For example, last year they published a study on peoples' tendency to see faces in the front of cars (you can't get more urban than that!) Apparently, about a third of subjects in their study thought that the front of a car looked like a human or animal face, with the headlights representing eyes and the grill or bumper representing a mouth. The testers then asked the subjects to rate the personality traits or emotions they associated with that face, and how much they liked the car. Interestingly, both men and women preferred cars with "faces" that were "mature, dominant masculine, angry-looking". Some have suggested that this preference may be due to a desire to appear more dominant during the daily interactions of driving, although it's unclear how wide spread the appeal of angry cars might be. After all, just look at the popularity of VW Bugs - and they certainly don't look arrogant or angry to me! If nothing else, this provides a counter-theory to my earlier presentation of Geoffrey Miller's theory of why we buy fancy cars: maybe, instead of hoping to impress others with a given brand, we are trying to impress them with a car that looks dominant or aggressive (in its "face"). And maybe those are both ways of saying that we, as social animals, are often driven to purchase items that imply status or dominance.

Besides giving some insight into our habits as shoppers, this finding is also a great example of the human capability for face perception. Spotting faces is so important to us that it occurs separately from other aspects of vision (most visual processes occur in the occipital lobe, but the part that identifies faces is in the temporal lobe). Moreover, damage to the temporal lobe can cause prosopagnosia - the inability to recognize familiar faces - without affecting any other aspect of vision. This impairment is the type of disorder that excites neuroscientists, sparking a huge amount of research - and with good reason, as the situation itself is so bizarre. Imagine, if you can, clearly seeing the faces of your loved ones, but being unable to identify them! And, more than dramatic value, this disorder has been vital in pinpointing the area of the brain involved in face perception.

One would imagine that someone with prosopagnosia would NOT be likely to see faces on cars - or images of God in a cloud or the Virgin Mary on a slice of toast, for that matter.

From Boingboing

This is the other side of the coin from those who can't recognize faces at all: the over-identification of faces where there are none! The New York Times summarized the phenomenon, explaining how the brain is so efficiently wired to detect the pattern of a human face that it sometimes picks up on faces where there are none. You could say that with the temporal lobe is designed to see images of Jesus and Che Guevara in potato chips and tree trunks, it's no wonder this occurs so often.

Clearly, the ability to recognize faces was very important in our evolutionary development. This is not too surprising - after all we are social creatures who experience the world through vision (as opposed to sound or smell or electromagnetism, like other animals). Moreover, being able to recognize each other and identify individuals is probably crucial to some of our more complex cognitive abilities (like reciprocity or theory of mind). Whatever the evolutionary explanation, the ability to recognize faces accurately appears to be so important that its worth it to err on the side of over-sensitivity (seeing faces in cars, for example) than miss a face.

Cockatoos and coffee

2009-06-08T15:30:00.000-07:00

I'm planted in the neighborhood coffee shop (Cafe Vivace), across from a woman with a cockatoo on her shoulder. Everyone in the room is ignoring her, focused on their laptops and newspapers. It's not too surprising - I've seen her here often, and one could assume that most of the customers here in the middle of the afternoon are regulars as well - until you stop and think about it. I've mentioned before my amazement at the human ability to ignore the wildlife that we've become habituated to, barely seeing the crows, pigeons, and squirrels we share our city with. These are animals that we see every day; interesting, then, that the same phenomenon can hold true for an animal that is comparatively rare, and certainly not native to this area. This seems to me to illustrate beautifully the way the human mind often works: willing to accept as "normal" many objectively unusual situations or images. Cockatoos are known to be pets, however uncommon, and thus the sight of a pet with its owner is accepted as normal; if the woman had a pigeon on her shoulder, perhaps she would draw more attention, despite the fact that pigeons are far more common! Or perhaps the lack of reaction is socially driven; no one else is responding to the bird, so we all comply with the social norms in the room. If someone made a big fuss over the birds, perhaps the rest of us would react more strongly? I don't know a lot about these types of issues, not being a social psychologist by training, but it is thought-provoking to consider what we perceive to be "normal" and why...

Marshmallows and success

2009-06-05T10:41:00.000-07:00

Last month, the New Yorker published an article about some research - the so called "marshmallow experiment" - from Bing nursery school at Stanford in the 1960s. Having spent some time as a researcher at Bing myself, I was interested to see it getting so much attention. The article beautifully describes a famous experiment in which children were placed in a small testing room with a marshmallow. The researcher told each child that they were going to leave the room, and that the child had two choices: they could eat the marshmallow immediately, or they could wait for the researcher to come back, at which point they would get two marshmallows. The experiment was a test of self-restraint - some children who could sit in a room alone with the treat for several minutes and patiently wait to double their payoff, while others gobbled up the marshmallow right away, and still others agonized over it, sniffing and staring at the prize before finally giving in to temptation. The research showed that children varied in their ability to hold off, and that those who were most successful at maintaining self control were those who were able to distract themselves (by singing a song, for example). If the researchers taught the kids a strategy, like pretending the marshmallow was actually a cloud, they did better at resisting temptation.

All of this was interesting, but the really cool results came 14 years later when the same children were graduating from high school. A follow up study showed that children who had easily resisted the marshmallow as preschoolers also had significantly higher SAT scores and high school GPAs. Apparently, being able to control your impulses, even at the age of 4, is a strong predictor that you will be able to control your impulses later in life (say, by forcing yourself to do your homework or focus on an exam). The New Yorker article describes how the researchers responsible for the initial marshmallow study and it's follow up (notably, Walter Mischel, a famous personality psychologist) are now doing a third series of tests with these same subjects, now adults. The studies are looking at the long-term effects of being a marshmallow-resistor (i.e., did those who were more self-controlled as children achieve a higher level of education, or attain more high-powered jobs?). They're also going to do brain scans to see which parts of the brain might be different between the two groups, and look at the heritability of self-restraint (i.e., are marshmallow resistors' children also able to pass the test?)

It's not really surprising that self-control would have a genetic component (like it or not, most of our behaviors do!), but it's interesting to me that behavior would be so consistent throughout the life, and that behavior in one context (marshmallow resisting) would translate to so many other contexts (studying, etc.). As Mischel himself has pointed out, human behavioral patterns are often context specific (that is, I could be shy at parties, but chatty one-on-one). With that idea in mind, it is fascinating that self-restraint is the same in so many areas; I would think that it might vary depending on the reward. That is, someone might be able to show self-restraint if there's an immediate or concrete reward (for example, a marshmallow!) but not if they're achieving something more abstract (the reward of increasing their knowledge, say). On the other hand, perhaps that's exactly why marshmallow performance correlates so well with grades and performance on standardized tests: those are other arenas where the reward is somewhat tangible (a better grade or score).

This all begs the question, how do we measure success? The marshmallow study implies that those who are naturally able to practice self-restraint, or those who are able to develop those skills through practice, will be more "successful". They will perform better academically, earn more money, and even weigh less than their undisciplined counterparts (seriously, BMI is one thing they're looking at). However, saying that these people are more successful is a function of the way that we define success in our society. By insisting on measuring success at all, we are limited to using variables that we can quantify (wealth, test scores, and weight being perfect examples). Thus, the highest educated, most academically competent, fittest person is judged to be the most successful - take our president as a prime example.

But what about other types of success? The New York Times Magazine recently published an article called "The Case for Working with Your Hands" about the pleasures and challenges of manual labor. The author, Matthew Crawford, was "successful" in the traditional sense - earning a PhD in political philosophy and working a high powered job at a policy organization in Washington D.C. However, as he describes in the article, he eventually left this "success" for a more fulfilling career - as a motorcycle mechanic. Here is someone who almost certainly would have passed the marshmallow test, but who found that even though he had the ability to achieve what he was told he should want in life, it did not actually make him happy. His argument is that many jobs that we commonly consider "blue collar" or "unskilled" because they don't require a post-collegiate education actually do require a great amount of skill and knowledge. We need to stretch the definition of success to include these types of jobs, rather than perpetuating the (ridiculous) idea that everyone should be aspiring to work in "policy organizations" and other office jobs. After all, as the marshmallow study shows, some people are not naturally suited to those types of careers. Perhaps, as Mischel showed, we can teach them some interventions to help them perform one-minded, focused jobs, but will they ever be able to actually enjoy them? Psychology keeps demonstrating that individuals vary on almost every spectrum imaginable (self-restraint being just one of them); now it's time for our culture to catch up with our science and start embracing those differences.

Survival of the shopper?

2009-05-19T15:56:00.000-07:00

There's an interesting article in the New York Times today by John Tierney about the science behind consumerism. Tierney summarizes some ideas from Geoffrey Miller at the University of New Mexico about why we buy what we buy, and what evolutionary theory can tell us about the human predisposition to brands. Basically, the argument that Miller makes is simple: we like expensive brand names because they are "costly signals" that can advertise our fitness to potential mates or allies. Miller claims that

"Harvard diplomas and iPhones send the same kind of signal as the ornate tail of a peacock.Sometimes the message is as simple as “I’ve got resources to burn,” the classic conspicuous waste demonstrated by the energy expended to lift a peacock’s tail or the fuel guzzled by a Hummer. But brand-name products aren’t just about flaunting transient wealth. The audience for our signals — prospective mates, friends, rivals — care more about the permanent traits measured in tests of intelligence and personality."

I agree that this makes sense in some cases where a consumer is deciding between two similar products with different brand names - they may choose one over the other purely because of it's fitness communicating value (an obvious example of this would be choosing between clothing items with prominent brand names, or perhaps, as Tierney suggests, choosing between a BMW and a less flashy car with an equally fast acceleration). However, in the entire article, Tierney only mentions in passing that there may be "other reasons for going to Harvard... or buying an iPhone." Of course there are! My problem with the article is that these "other reasons" are probably far more powerful in making a decision than the "costly signaling" impulse Miller fixates on.

Miller's experiments show people are more willing to purchase products if they are primed with pictures of the opposite sex or stories about dating (that is, they associate the product with increased mating opportunities), which is his primary support for the position that we buy things to attract mates and impress strangers. Fair enough - communication of status as a good mate is important and is surely something that natural selection would select for. However, just because this may be one factor in our decision making, it doesn't make it the only factor (or even the main factor!). To be fair, I haven't read Miller's book, so maybe his argument is more nuanced there; however, as presented in the article, it appears a statement of fact - a broad, over-generalization of a single idea to explain a whole slew of behaviors. Such generalization is often very tempting when studying behavior (or when reporting on it, as the case may be... again, I don't know where the blame lies on this one), but it's important to be more subtle. Indeed, this is one of the great frustrations of behavioral research - individual variation!

A final complaint with the article: Miller (via Tierney) concludes that this consumer signaling is an evolutionary misstep, not actually adaptive in most situations. He claims that people actually judge each other mostly by their personality and intellect, not by their possessions, and calls the consumerist urge to impress others via costly signals and brand names "a quirky evolutionary byproduct of a smaller social world." However, this conclusion seems idealistic, another generalization from someone who naively believes that "it's what's inside that counts". Again, independent of whether an item's potential signal value is the primary motivation in making a purchasing decision, it probably is a factor because we do "judge books by their cover". As Malcolm Gladwell will tell you, human interactions are full of snap judgements; whether we talk to a stranger of the opposite sex (a potential mate) is likely to be directly related to what they're wearing, for example. Obviously, as Miller suggests, the impression you make on someone else is based on you, not your possessions; but your possessions certainly play a role in whether or not you have an interaction.

Overall, I don't think Miller is wrong, he's just overgeneralizing on all of his ideas. It's as if there can't be two explanations for a single event, or two phenomenon contributing to the same result. Many factors affect what we buy; one is likely potential signaling value of a brand. Similarly, many factors contribute to who we meet and the impression we make; personality is probably the main one, but there's no reason that brand signals can't contribute.

Why we hate Madoff

2009-05-15T07:14:00.000-07:00

Evolutionary biologists have put a lot of thought and effort into explaining an aspect of human nature that's both fundamental and mysterious: why are we nice to each other? Altruism is baffling because at first glance, it seems to go against the grain of natural selection. Why waste your energy and resources on others, when the point of existence is to multiply your own genes? Every man for himself! But that's not what we see, so several explanations have been concocted to understand why, in the end, we are willing to help each other out.

The most common reason for altruism in the animal world seems to be kin selection - helping out copies of your own genes which just happen to be in other bodies. But another form of altruism - one that humans excel at - is reciprocity. This explanation, first suggested by Robert Trivers in the early '70s, goes something like this: we help out others in need so that they'll help us out when we need it (basically, "you scratch my back, and I'll scratch yours"). Reciprocity turns out to have limited applications in animals, probably because most animals don't have the cognitive capabilities to recognize an unrelated stranger, calculate how likely they are to see that stranger again, and then keep careful score of who helped who when. Humans, on the other hand, definitely have these capabilities, and we make constant use of them. Our brains include a complex social scoreboard: who gave me a Christmas present last year? Who took out the trash last week? Who arranged the last date? We remember these details, and respond appropriately : giving presents to those who gave to us, taking turns with chores, alternating who calls who. A lot of basic human social interactions are based on this engrained expectation of quid pro quo, which is perhaps why we get so angry when these "rules" are violated.

This brings me around to the financial crisis. In a sense, our entire financial system is based on the human tendency for reciprocity - we make investments or loans expecting to be reimbursed - and in that way, one could say that the financial crisis was caused by a break-down of reciprocity. People defaulted on their mortgages, investors bought worthless toxic assets. The honesty required for a reciprocal system to function broke down, and we were left with a system riddled with "cheaters" (whether intentional or not, accepting but not reciprocating makes one a cheater in a reciprocal interaction).

Perhaps the most famous "cheater" to emerge from this crisis was Bernie Madoff, the Ponzi schemer who lost his clients almost $85 billion. That's an enormous amount of money, and so much of the outrage over the incident has probably been due to that fact alone: Madoff was a thief on a huge scale. For perspective, the largest bank robbery in history, according to Wikipedia, was the 2003 robbery of the Central Bank of Iraq, in which about a billion dollars were stolen. While the scale is obviously quite different between these two "robberies", I'm not sure that the public reaction has been to scale. To me, it seems that Madoff has generated more than 85 times the media coverage and anger than the CBI incident did, and one possible explanation for this is that he violated our basic human instinct for reciprocity.

I expect there is also a natural human aversion to thievery, but it might not be as strong. Thieving might have served our ancestors at some point in our evolutionary past; being willing to scavenge, to take what is available, probably translated into better survival. Perhaps this is why we have such mixed feelings on the subject, teaching that "Thou shalt not steal" but simultaneously heroizing Robin Hood. There is no "Robin Hood" equivalent of a hero who takes what is given to him but doesn't reciprocate. Thus, it makes evolutionary sense to me that the inclination not to steal is a cultural mandate, something that we must be taught, while the instinct for reciprocity is an evolutionary strategy that lies deeper. This would explain why we hate Madoff so much, and why he has been portrayed as such a villain: he violated one of the fundamental rules of human social interactions.