Awesome takedown of several evolutionary psychology claims

[marydell]

This article gives an overview of a lot of the popular evolutionary psychology claims of the last 20 years--gender-based differences in jealousy, men's universal preference for hourglass female figures, rape as an adaptation that improves men's evolutionary fitness (ie ability to successfully propogate their genes), killing of stepchildren as a similar adaptation--and the actual scientific evidence that shows they're basically  horseshit. AWESOME.  Excerpt concerning rape: 

Hill had something almost as good as a time machine. He had the Ache, who live much as humans did 100,000 years ago. He and two colleagues therefore calculated how rape would affect the evolutionary prospects of a 25-year-old Ache. (They didn't observe any rapes, but did a what-if calculation based on measurements of, for instance, the odds that a woman is able to conceive on any given day.) The scientists were generous to the rape-as-adaptation claim, assuming that rapists target only women of reproductive age, for instance, even though in reality girls younger than 10 and women over 60 are often victims. Then they calculated rape's fitness costs and benefits. Rape costs a man fitness points if the victim's husband or other relatives kill him, for instance. He loses fitness points, too, if the mother refuses to raise a child of rape, and if being a known rapist (in a small hunter-gatherer tribe, rape and rapists are public knowledge) makes others less likely to help him find food. Rape increases a man's evolutionary fitness based on the chance that a rape victim is fertile (15 percent), that she will conceive (a 7 percent chance), that she will not miscarry (90 percent) and that she will not let the baby die even though it is the child of rape (90 percent). Hill then ran the numbers on the reproductive costs and benefits of rape. It wasn't even close: the cost exceeds the benefit by a factor of 10. "That makes the likelihood that rape is an evolved adaptation extremely low," says Hill. "It just wouldn't have made sense for men in the Pleistocene to use rape as a reproductive strategy, so the argument that it's preprogrammed into us doesn't hold up."

Concerning sexual jealousy:
 

In questionnaires, more men than women say they'd be upset more by sexual infidelity than emotional infidelity, by a margin of more than 2-to-1, David Buss of the University of Texas found in an early study of American college students. But men are evenly split on which kind of infidelity upsets them more: half find it more upsetting to think of their mate falling in love with someone else; half find it more upsetting to think of her sleeping with someone else. Not very strong evidence for the claim that men, as a species, care more about sexual infidelity. And in some countries, notably Germany and the Netherlands, the percentage of men who say they find sexual infidelity more upsetting than the emotional kind is only 28 percent and 23 percent. Which suggests that, once again, it depends: in cultures with a relaxed view of female sexuality, men do not get all that upset if a woman has a brief, meaningless fling. It does not portend that she will leave him. It is much more likely that both men and women are wired to detect behavior that threatens their bond, but what that behavior is depends on culture. In a society where an illicit affair portends the end of a relationship, men should indeed be wired to care about that. In a society where that's no big deal, they shouldn't—and, it seems, don't.

And concerning body type preferences:
 

 

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.

Comments

[cathshaffer.livejournal.com]

Modern homo sapiens begins around 40,000 years ago. That is when grave goods and evidence of religion begin to appear in burials, and it is also when many anthropologists believe that language emerged. We cannot but be pretty much genetically identical--40,000 years is not much. Modern homo is also the product of a pretty severe bottleneck (I forget the dates) so that we are even more identical to each other than most other species on the planet. So little is known about the genetic basis of behavior, however, that it is possible that tiny changes make a big difference. Possibly even epigenetic changes that do not appear in the DNA code itself.

Such a fascinating topic, and interesting comment threads.