I wrote this post almost a year ago, but it's always been my plan to add to it. And now Echidne (who is, among other things, a tireless debunker of gender-essentialist pop evolutionary psychology) has inspired me to come back to this topic.
She describes a recent study in Evolution and Human Behavior (full text here) by Jaime C. Confer, Carin Perilloux and David Buss that tried to characterize how men and women choose short-term or long-term sexual partners.
Briefly, what the study did was sit 192 straight male and 183 straight female (the six --- only six?! --- would-be participants who said they were gay were screened out) college students down and show them a (clothed) picture of a member of the opposite sex, whom they were supposed to evaluate as a potential sex partner. (Half of them were told to consider the person as a short-term partner; the other half were told to think long-term). The picture was initially covered up, with one box covering the face* and another covering the body; study participants were given a choice which box to remove.
When evaluating the pictured person as a potential long-term sexual partner, the sexes behaved almost identically: sixty-eight of the men (75%) and sixty of the women (73%) chose to look at the person's face. The sexes also showed a similar change in strategy between long- and short-term conditions: both looked at the face more when they were asked to evaluate a potential long-term partner, and both looked at the body more when asked to evaluate a potential short-term partner. For the men, though, the change in strategy was much more dramatic: they went from three-quarters of them choosing the face in one set of circumstances to half and half in the other (roughly speaking); for the women, it was a much smaller decline, from (a little less than) three-quarters to two-thirds. The men's change, but not the women's, was considered statistically significant.
That's not the narrative Confer, Perilloux and Buss use to describe their findings, though: rather predictably, they see a marked sexual dimorphism in mate-choosing strategies, reflecting deeply ingrained male preferences for fertile mates (i.e., younger women with neotenous, "hyperfeminine" facial features as long-term partners, but also obviously sexually mature, fertile women with low waist-to-hip ratios as short-term partners) and an equally ingrained lack of female preferences for youth or bodily beauty in her partners.
The study, its findings, and the way its authors chose to present those findings are not what I really want to look at in this entry, though. (Echidne has already covered those angles really well). No, what I want to look at is the imaginary scenario the study's authors set up for its participants: what they were asked to do, essentially, is evaluate a third (absent) person's suitability as a sexual partner based on one quick look.
It came up in the comments at Echidne's blog, and I agreed wholeheartedly, that this scenario resembles today's anonymous, superficial meat-market dating scene a lot more than it does the likely pattern of courting and mating behaviors that early humans would've shown. Early humans, like other primates and modern-day humans still living a hunting-and-gathering lifestyle, lived in small, close-knit bands, where you would probably have known the people you ended up having sex with for quite a long time before you had sex with them. Accordingly, things like waist-hip ratio, facial symmetry and whatnot would've been less important than, say, each partner's social and family ties (i.e., does she have sisters, aunts or a mother who would help out with childcare? Do these aforementioned relatives *like* the prospective mate? What about his relatives? How does he get along with the other men in the tribe? Is he a social asset or liability?) or lack thereof.
This is another of the weird things I've noticed about much of evolutionary psychology --- it seems to be less a historical science (like paleontology or archaeology) and more an extended thought-experiment in What Human Nature Would Be Like If It Weren't for All This Pesky Civilization Crap. The ev-psych model for heterosexual relationships seems to assume that the man and the woman are both relatively isolated: the woman depends solely on the man for support, for herself and her children; the man, while he is not correspondingly dependent on the woman, and is thought to be impregnating --- or trying to impregnate --- other women whenever the opportunity arises, his relations to other men resemble the Hobbesian state of "war of all against all." (Similarly, other women are invisible unless and until the man in the thought-experiment has sex with them).
This highly individualized, atomistic way of thinking about people is actually very new in the history of ideas, and notably it does not compute to modern-day people who actually live in extended-family communities.
*This experimental setup apparently poses a temptation for commentators to make "butterface" jokes. I am trying to resist this.