Tuesday, April 12, 2011

An Old Evo-Psycho Study Still Worth Ripping Apart

This one was popularized almost a year ago. Which is nice because we don't have to think of its influence spreading everywhere right now. The reason I'm writing about it is its perfection as an example of what is wrong with evolutionary psychology of the weird kind (the kind some call EP as opposed to ep and the kind I call evo-psycho) or at least with its customary popularizations.

Here is a summary of the study:
Men weigh up potential partners almost instantaneously based on their appearance because their "ancient" genetic preference for attractive mates leads them to, experts claim.
According to research, a woman with an attractive face is taken by men to be fertile and able to continue the family line, appealing to the man's survival instinct.
In contrast women take longer to decide their feelings for a man because they need to weigh up whether he will be a committed partner who will provide for them well – part of their survival programming.
Professor Mark van Vugt and Dr Johanna van Hooff, from the University of Amsterdam, and postgraduate student Helen Crawford, from the University of Kent, were behind the study which is to be published by the Oxford Journal Social Cognitive and Affective Neuroscience.
They tested men and women's bias towards looks by conducting a series of tests on 20 women and 20 men, making them perform tasks while recording their brain activity.
While the subjects were doing the task they were shown a series of photographs of faces of the opposite sex, ranging from attractive to ugly.
Men were easily distracted when they saw a pretty face but women stuck to the task.
And the conclusions? Here they are:
Prof van Vugt said: "Men definitely have the most wandering eye but it is because they have evolved to pay attention to cues of fertility and one of those cues is facial beauty – it's not that men are shallow.
"But we found they do make snap judgments about women, much earlier than was previously thought. They make that decision on whether a woman would be a good mating partner in milliseconds.
"This is something very ancient and a way of helping men find the best mate to produce children.
"Women were not distracted by attractive male faces because women need more proof of whether a man is a good mate.
"Women make that decision on behaviour, whether a man is trustworthy and committed. They make their decision much later than men."
Let's slow down a bit and look at what all this says. The steps:
1. A study found that men were more distracted by pictures of beautiful women than women were distracted by pictures of beautiful men in some artificial setting in which everyone was doing assigned tasks. It is not clear if all the participants were heterosexual and it's pretty much impossible to know the details of the study. But let's assume that all this is true.

Does this then follow?

2. This means that men are ready to mate with those beautiful female faces they were distracted by and that women are not ready to mate with those beautiful male faces they were not distracted by. Were the study subjects asked to think about mating with the faces or not? Because if they were not asked to do that, it's hard to know what the impact of the faces would be. In terms of mating behavior, that is.

But suppose that you even accept part 2. Does this then follow:

3. All this proves that men go for a pretty face as a sign of good fertility whereas women need more time to find a good provider. Note that the actual evidence for this final conclusion is that "Men were easily distracted when they saw a pretty face but women stuck to the task." There are other explanations for why men might be more easily distracted by women, having to do with who it is who is expected and allowed to react to attractive individuals in this society and so on.

Get what happened there? A particular study was generalized in two stages, both of them giant leaps, and only one possible final interpretation was offered.

But in fact, as I have written many, many times before, we don't know how prehistoric humans decided on their mating partners (if they were allowed to decide in the first place), and at least I don't know any evidence which tells us that women regarded as more beautiful today are also more fertile than women regarded as ugly today. Beauty ideals do change, you know. If you doubt me have a look at collections in art museums.

Yet the kinds of tenuous ties used in this popularization are common. I often get told that science has "proven" that men are hard-wired to look for one thing and women for another thing based on our prehistoric past. Yet our knowledge of the events in that prehistoric past is mostly nothing but guesses by currently living individuals who never visited that mythical place where all adaptations were supposed to have happened.

This cartoon (unrelated to the study) is ultimately part of the same movement as the evo-psycho popularizations (to justify traditional sex roles and perhaps to make fun of women), but it exploits the past in a more honest way. None of us are led to believe that "cavemen" had such discussions, after all. It's an invention and open about being an invention (though less open about attributing the task of cooking to women only). I wish the same was true about the weird branch of evolutionary psychology.
Link by Jennifer in the comments.