Neuroanthropology

Live Science has a recent piece, Why We Fear Snakes, written by Clara Moskowitz. I have to admit that, well, I hate this sort of thing for so many reasons that I hesitate to write. My problem with these accounts is with ‘innate’; I think the term is, generally, poorly defined, unprovable and unproven, sloppy, theoretically suspect, and freighted with so many dangerous implications that it gives me, for want of a better word, the heebie-jeebies.

Before I get too critical, however, it’s necessary to acknowledge that some of the assumptions I’ll critique may have, likely have, arisen in the translation of a complex research project into a few hundred words for a popular press account. God knows my own work has suffered when it’s been translated into popular formats (don’t even get started about a CNN special on race that I was interviewed for…). We’re encouraged to do outreach to the community, to put our specialties up on ‘expert’ databases and basically pimp ourselves for any positive reference, so we wind up bending over backwards to make our ideas accessible. This can lead us to stumble, especially in the view of a discipline that doesn’t share our concerns. For example, if I were to try to give an accessible account of my work, a neuroscientists would likely gag on some of the explanatory shortcuts. So some of the criticisms that I will level might be better applied to the science writer rather than the researchers; we’ll know when the research findings are eventually published. Caveats in place, on with it…

Apparently, the Psychology Department at the University of Virginia has a couple of scholars studying the ‘universal’ fear of snakes. The piece says what one might expect: ‘The researchers were inspired to investigate the fear of snakes when they thought about how universally people dislike the slithering legless lizards. “This feeling is really common,” [Vanessa] LoBue told LiveScience. “We don’t see snakes all the time. There’s really no reason for this overwhelming disgust or hatred of snakes.”‘ The researchers demonstrated this universal fear by showing that both adults and children ‘could detect images of snakes among a variety of non-threatening objects more quickly than they could pinpoint frogs, flowers or caterpillars.’ And the explanation is that an innate fear of snakes would have made humans more likely to survive in the wild.

Why does this stuff drive me nuts? Well, first of all, it’s evolutionary psychology’s typical modus operandi: notice something normative in your life, assume that it’s universal, and then make up an evolutionary ‘just so’ story that ‘explains’ one’s own normative construct. We can make them up for Western biases about female beauty, alleged age differences in ideal mates, obesity trends, etc. etc. A while back, I mentioned an evolutionary psychology bingo card Savage Minds posting that mocked these stories, using the example of ‘women’s love of pink things’ and a contrived story, but the master of attacking adaptationist ‘just-so’ stories was the late Stephen Jay Gould.

Although I love the University of Virginia (my alma mater) and the field of psychology (well, some of the time), I fear that the research team has done exactly what Gould cautioned against. One of the research team, professor Judy DeLoache tells the interviewer: ‘I have almost a phobia of snakes… When I see a picture of a snake, I’m like, “Oh my God, eew!” The reason we got into this research was because I’ve always been fascinated by how it is that people develop it. My intuition was that there was something that made me feel afraid of snakes early on. You react to them very early on.’ Do you?

In fact, the story goes on in a few paragraphs to contradict the assertion that a person reacts to snakes ‘very early on.’ As Moskowitz writes: ‘While babies and very young children do not usually fear snakes, they are unusually skilled at detecting them and show a predisposition to learn to fear snakes if they have bad experiences or even if they are exposed to negative portrayals of them in the media, the scientists found.’

Hold on, so very young children do not usually fear snakes but are ‘predisposed’ to detecting them? Although the interpretation of the research significance is that we have a ‘universal fear,’ in fact what the research showed is that we seem to be good at detecting snake shapes. The research team ‘showed adults and 3-year-old children images of a snake surrounded by objects of similar colors, such as frogs, caterpillars and flowers. Then they showed them pictures of a frog or a flower surrounded by snakes. Both groups were able to identify the hidden snake faster than the other hidden objects.’

I’m not convinced that this is a test of fear of snakes. It might be a test of perceptual salience of snake-shaped objects and much more complicated, non-linear objects. The ‘predisposition,’ as the researchers put it (again, it’s hard to know what they said and what the science writer got them to say in interview), may in fact be perceptual, a propensity may have a lot to do with the physical traits of snakes themselves (in fact, we also may find widespread fears of snake-like animals, because they have certain traits — I’m thinking of lizards, other reptiles, legless animals including insects…). Or it might have to do with the salience of shapes in the visual field. And, in addition, if you were going to program a human with an innate predisposition to detect snakes, wouldn’t it be better to have a tendency to detect the way that they move?

And then there’s the more general problem of adaptationist explanations; if it’s good for one alleged evolutionary ‘need,’ why didn’t it work for others? According to About.com (no authority, but easy to find), the ten most common phobias include snakes and spiders, as the team’s research suggests, but they also include heights, small spaces, dogs, thunder and lightening, injections, social situations, flying and dirt and germs. Other lists include fear of water (especially open water), public speaking, public transportation, tunnels, and bridges. Okay, so what is the evolutionary story we’re going to come up with to explain the widespread fear of injections, public transport, and bridges? Too many hypodermic needles, dangerous subways, or single span arches in the evolutionary environment? How about fear of public speaking or social situations? Maybe large groups attracted predators? And fear of water or dirt? This could post some problems for anyone living in by foraging, I would guess. I don’t mean to belittle the research, but the agenda cherry picks which phobias to focus on. If one is an adaptation, why aren’t the others?

Moreover, it leaves out the fact that we are NOT afraid of many of the really dangerous things out there. For example, some people are afraid of dogs; a large number of people, however, are deeply attached to these potentially dangerous carnivores and keep them around — there’s two of them sitting within easy striking range of me as I write this. Wild boars, hippopotami, elephants, blue-ringed octopi, box jellyfish, poison arrow frogs, even the platypus… they’re all pretty dangerous, and some may even have the ‘eew’ factor, but I don’t know if people have real full-blown phobias about them. In fact, the real killer animal out there is not poisonous snakes — mosquitos kill around 2 to 3 million people a year, so evolution has been really slack not giving us all a good, widespread mosquito phobia. But this pales in comparison to the most dangerous creatures to humans: other humans. (So perhaps fear of social situations is more adaptive than I was suggesting.) In other words, if one is going to argue that fear of snakes and spiders is an adaptation to the danger they posed, then explaining the absence of fear of other dangerous things gets complicated.

The next problem with the ‘fear of snakes’ as evolutionary adaptation argument is the universality problem: is fear of snakes in fact ‘universal’?  Well, it may be widespread, but there are people who keep snakes as pets, so whatever else we can say about those folks, they do seem to undermine a certain interpretation of ‘universal.’  This is a constant problem with ‘innate’ traits — what if someone doesn’t have them? Fear of snakes is not even universal in animals; as R. A. Hinde (1991) pointed out, monkeys raised in laboratories don’t demonstrate a fear of snakes.  And living in Australia, I know that not everyone is ‘afraid’ of snakes in an identical, universal sense. Although we’re surrounded by some of the more poisonous snakes on the planet, my neighbors and I have discussions about which snakes really need to be killed and which ones should actually be left alone because, although they are poisonous, they seem to keep away even more poisonous, more aggressive ones because some snakes are territorial (yeah… I’m still not so sure about that one, but I believe in trusting local knowledge).

The final problem that ‘innate’ brings up is the question of the mechanism that produced the trait. In much of the discussion, there’s an assumption that there must be a ‘gene for’ something if it is ‘universal’ and ‘innate’ (although I find no evidence of genetic explanations in the fear of snakes story). In fact, there’s never much discussion of the actual mechanism that might turn an alleged gene into an innate trait. What sort of protein might produce fear of snakes? What parts of the brain would it interact with? Do we see any mutations of it that produce other similar phenomena? In other words, there’s a ‘black boxing’ of mechanisms, an unwillingness to think about how the trait might actually arise in a developmental context or function in an organism.

In fact, Hinde’s approach to fear of snakes is far more measured than DeLoache and LoBue, even using some of the same terms (like ‘predisposition’) and he doesn’t rely quite so much on the idea that evolution programmed us with some sort of innate fear (that some people don’t seem to demonstrate). Hinde argues that humans are ‘predisposed to acquire a fear of snakes,’ not that such a fear is inherent in being human: ‘Anecdotal evidence suggests that the extent ofthe fear shown is much influenced by social referencing – the child looks at others, and especially at a trusted other, and models his or her response to the situation according to the response of that other.’

‘Predisposition’ is a vague term, a lot less interesting in a short account than something described as ‘innate’ or ‘universal.’ But it’s also an evidence-based term, one that notices the exceptions and variations in people’s attitudes toward snakes. An account of an ‘innate’ tendency is quick and dirty, turning observations of behavior into putative ‘gene’ or some innate essence and linking them both to an evolutionary ‘explanation’ which is untestable but plausible. Snakes are dangerous; we tend to fear them (though not always); so we must have some essential part of us that produces this fear (although we can’t identify that part or explain how it works). A more complex, dynamic account of how fear might arise, taking into account factors like the material quality of snakes, perceptual dynamics, and social reinforcement, won’t be as easy to fit in a short article, but it has the advantage of better accounting for the variations, the people who aren’t afraid, and a host of other factors that the ‘innate-ist’ account has to simply ignore.

References
Hinde, R. A. 1991. A Biologist Looks at Anthropology. Man (New Series) 26(4): 583-608.