Source [http://www.newsweek.com/id/202789/page/1]:
That is what a new wave of studies has been discovering, slaying assertions about universals right and left. One evo-psych claim that captured the public's imagination?and a 1996 cover story in NEWSWEEK?is that men have a mental module that causes them to prefer women with a waist-to-hip ratio of 0.7 (a 36-25-36 figure, for instance). Reprising the rape debate, social scientists and policymakers who worried that this would send impressionable young women scurrying for a measuring tape and a how-to book on bulimia could only sputter about how pernicious this message was, but not that it was scientifically wrong. To the contrary, proponents of this idea had gobs of data in their favor. Using their favorite guinea pigs?American college students?they found that men, shown pictures of different female body types, picked Ms. 36-25-36 as their sexual ideal. The studies, however, failed to rule out the possibility that the preference was not innate?human nature?but, rather, the product of exposure to mass culture and the messages it sends about what's beautiful. Such basic flaws, notes Bingham, "led to complaints that many of these experiments seemed a little less than rigorous to be underpinning an entire new field."
Later studies, which got almost no attention, indeed found that in isolated populations in Peru and Tanzania, men consider hourglass women sickly looking. They prefer 0.9s?heavier women. And last December, anthropologist Elizabeth Cashdan of the University of Utah reported in the journal Current Anthropology that men now prefer this non-hourglass shape in countries where women tend to be economically independent (Britain and Denmark) and in some non-Western societies where women bear the responsibility for finding food. Only in countries where women are economically dependent on men (such as Japan, Greece and Portugal) do men have a strong preference for Barbie. (The United States is in the middle.) Cashdan puts it this way: which body type men prefer "should depend on [italics added] the degree to which they want their mates to be strong, tough, economically successful and politically competitive."
Depend on? The very phrase is anathema to the dogma of a universal human nature. But it is the essence of an emerging, competing field. Called behavioral ecology, it starts from the premise that social and environmental forces select for various behaviors that optimize people's fitness in a given environment. Different environment, different behaviors?and different human "natures." That's why men prefer Ms. 36-25-36 in some cultures (where women are, to exaggerate only a bit, decorative objects) but not others (where women bring home salaries or food they've gathered in the jungle).
And it's why the evo psych tenet that men have an inherited mental module that causes them to prefer young, beautiful women while women have one that causes them to prefer older, wealthy men also falls apart. As 21st-century Western women achieve professional success and gain financial independence, their mate preference changes, scientists led by Fhionna Moore at Scotland's University of St Andrews reported in 2006 in the journal Evolutionand Human Behaviour. The more financially independent a woman is, the more likely she is to choose a partner based on looks than bank balance?kind of like (some) men. (Yes, growing sexual equality in the economic realm means that women, too, are free to choose partners based on how hot they are, as the cougar phenomenon suggests.) Although that finding undercuts evo psych, it supports the "it depends" school of behavioral ecology, which holds that natural selection chose general intelligence and flexibility, not mental modules preprogrammed with preferences and behaviors. "Evolutionary psychology ridicules the notion that the brain could have evolved to be an all-purpose fitness-maximizing mechanism," says Hill. "But that's exactly what we keep finding."
