I have very little patience for the amorphous field of "evolutionary psychology," which should be interesting in theory, but in practice tends to center around reinforcing retrograde gender roles with almost nothing in the way of substantive evidence or even logic to support its claims. Pointing this out will get you accused of being "anti-science"--even if you have, say, spoken about this topic at a pro-science conference to a largely positive reception, especially from biologists--so instead of trotting out the arguments for myself, I prefer to borrow the authority of people who only the daringly stupid would accuse of being anti-science. Which is how I'm going to approach contesting this article by Jesse Bering at Slate about the supposed evidence that women evolved to fight back against rape ... if they're ovulating.
The authority I'll borrow today is that of PZ Myers, a biologist who works at the University of Minnesota-Morris. He demonstrates that the evidence for the claims Bering makes for women's supposedly heightened unwillingness to be raped fails any reasonable sniff test. Most of the studies were conducted on small, homogeneous groups of women, using subjective measurements. Some of them failed to present the evidence that Bering suggests they have--the handgrip study was one where some researchers found no variation over a menstrual cycle. If Myers' authority doesn't satisfy you, I would also like to present Jerry Coyne, a biologist at the University of Chicago, and his points about how thin the evidence is for the claims presented.
The examinations of the evidence are the most important rebuttals here, but I would like to point out that there's also a conceptual error in Bering's piece. The understanding that rape is a violent crime that usually involves misogynist anger or contempt toward the victim is not really evident in the article. Myers touches on this in his critique:
Another way to look at it is that they are hypothesizing that women are more likely to behave in ways that invite physical attack and brutal abuse when they aren't ovulating. That is a remarkable assertion. It also carries the strange implication that the consequences of rape can be measured by the likelihood of immediate fertilization, rather than by the toll of physical injury and emotional trauma, a peculiar thing for psychologists to neglect.
Bering does take the time to suggest that rape is generally unpleasant, but he doesn't dwell on this, probably because thinking about that too hard really does call into question why on earth women would evolve to be less defensive of their personal safety just because they're not ovulating. But it also calls into question why Bering neglects to consider what makes rape more appealing to rapists than not raping. He assumes, without evidence, that the folk belief that rapists are just hard up for sex and can only get it through force is true. There's also the weird side assumption that features prominently in many half-baked evolutionary theories, which is that sex is strictly about reproduction in a species that has homosexuality, contraception, and old people who get it on.
To focus on the assumption about what motivates rapists, however: There's a countertheory to the "hard up" theory, which is that rape is a learned behavior, and that rapists get off not on the chance to plant their seed (some, after all, use condoms!) in an unwilling woman, but that they get the idea from the culture that sex is a way to dominate women, and forced sex is even more so. What's nice about the "men rape to dominate and hurt women" theory is that it's actually got evidence behind it.
Extensive research by psychologist David Lisak on rapists demonstrates that they, as a group, are more violent and obsessed with their self-image as tough, masculine guys than nonrapists. Men who rape aren't particularly hard up, but they are more likely to beat women and children, both of which are behaviors that do nothing to improve your reproductive chances. (In fact, domestic abusers are more, not less, likely to kill their partners when they're pregnant, the ultimate nonadaptive behavior.) Some of the studies on rapists Bering references make more, not less, sense if you apply the "rapists are violent" lens instead of the "rapists are just horny" lens to the situation. For instance, Bering says, "And spousal rape is most likely to occur when the husband finds out (or suspects) his wife has been unfaithful, suggesting that he is attempting to supplant another man's seed." Except I bet that a wife beating is exponentially more likely to occur after an infidelity is discovered, too. Rape, in this case, is just a certain kind of wife-beating. It's best understood as throwing a punch with your penis.
Even with his disavowals, the fact remains that Bering's article downplays the severity of rape. It suggests that there's not much to be done about rape and that men are just programmed to do it, and it distracts from the fact that it's a violent act, experienced by both victim and assailant as assault. There's no real reason to think men are programmed to rape, especially since rape rates plummeted dramatically after feminist activism discouraged the idea that men have a natural right to dominate women.