Tuesday, January 18, 2011

Anti-Rape Evolutionary Adaptations. Beep, Beep.

Some days all the topics I have lined up give me the same reaction, a desire to scratch my eyes out or to get my stomach lined with stainless steel. Today is one of those days.

Let's tackle the worst of those topics first: A story on Slate about how women have evolved to stop rapists from passing their genes on! If a story ever could be labeled "mansplaining" then it is this one. Notice the beginning:
Women, gather round, read carefully, because this gay man—who once, long ago, feigned sexual interest in your bodies—is about to shine a spotlight on some hidden truths about your natural design. It's by no means a perfect system, but evolution has endowed you with some extraordinary, almost preternatural abilities to prevent your own sexual assault. And these abilities are especially pronounced when you're ovulating.
Mmm. The idea is that men rape because it is an evolutionary adaptation, something that will let them pass their genes on when they otherwise could not do so.

But the women who get pregnant from rape have their own evolutionary plans completely messed up: They now have a low quality fetus and they must dedicate their scarce parenting resources to it instead of getting to choose some high-quality male for conception purposes. Score 1-0 to benefit the rapists, and the reason why Evo-Psychos (the nutty type of evolutionary psychologists) like writing about rape in these terms. Or so I think.

The idea that rape might be an evolutionary adaptation was fiercely debated some ten years ago when two EP guyz, Randy Thornhill and Craig Palmer, wrote a book about it called A Natural History of Rape. The basic problem with their thesis is that one might use pretty much the same arguments to bolster the thesis that serial murders are an evolutionary adaptation or that anything else that exists today must be an evolutionary adaptation.

That rape might be a spandrel, something that doesn't have any adaptive value in itself seems much more likely, if we decide to stay within the ep paradigm.

The Thornhill-Palmer theory also suffers from the usual lack of evidence: To prove that rape works that way one must show that rapists leave behind more children by raping than through alternative strategies. As far as I know, such evidence does not exist. In fact, the reverse might be more the case, given what happened to caught rapists in some places in the past.

Let's go back to the Slate piece. Its author, one Jesse Bering, argues, as is usual in this branch of literature, that anyone opposing his views suffers from various kinds of bad thinking:
Yet dilettante followers may still be inclined to detect a misogyny in these investigations that simply is not there. As University of Michigan psychologist William McKibbin and his colleagues write in a 2008 piece for the Review of General Psychology, "No sensible person would argue that a scientist researching the causes of cancer is thereby justifying or promoting cancer. Yet some people argue that investigating rape from an evolutionary perspective justifies or legitimizes rape."

The unfortunate demonization of this brand of inquiry is rooted in the fallacy of biological determinism (according to which men are programmed by their genes to rape and have no free will to do otherwise) and the naturalistic fallacy (that because rape is natural it must be acceptable). These are resoundingly false assumptions that reveal a profound ignorance of evolutionary biology. Yet the purpose of the remaining article is not to belabor that tired ideological dispute, but to look at things from the female genetic point of view. We've heard the argument that men may have evolved to sexually assault women. Have women evolved to protect themselves from men?
I love that cancer analogy, don't you? Except, of course, that nobody is trying to explain how cancer is sorta good for some of us, ultimately, and that's exactly what this particular approach to rape does. I also love the warnings about the two fallacies. These days they tend to be mostly used to cover up bad research and to insist that it shouldn't be criticized because criticizing it equals splashing about in those fallacy ponds.

Let's turn to the bits where Bering tells us how women, too, have evolved to protect themselves against having children by rapists! Note that the evidence cited in the article is not about women really having evolved to protect themselves against rape in general but only against the possibility of conceiving from a rape. As proof of that Bering lists several studies which appear to suggest that women are more careful and more frightened about rape during the time of their ovulation.

Now think carefully about that. Remember that this "evolutionary adaptation" is NOT the same thing as a woman thinking that she might get pregnant more easily and that therefore she should take special care around ovulation not to get raped because then rape would not just be a horrendous experience of violence but could also result in the need for an abortion. That's not what the evolutionary psychologists mean when they study the possible correlation between ovulation and rape prevention.

Rather, the ideal test of this all would be a situation where the woman doesn't know when she ovulates. If, under those conditions, her reactions to the possibility of rape would clearly vary by her menstrual cycle, then the "evolutionary adaptation" theory would have some possible credibility.

But the studies Bering mentions involve asking the women about their menstrual cycle! The studies are not double-blind ones, in the sense that neither the subjects nor the researchers would know at what stage of her cycle a particular woman is. They are not even "single-blind" ones, in the sense that the woman wouldn't know the stage of her cycle. What all this means is that we have no way of knowing if the observed variations are caused by what the women decide to do, quite explicitly, or if something else is going on.

All this is assuming that the studies themselves were properly carried out. The two studies Bering's links let me access don't provide any raw data or even basic frequency data, and at least one of them has serious problems with the way risky behavior is defined (because the same behavior, say, going out to a concert dressed in a sexy dress with a relative stranger would score in three categories, not just one).

But don't worry your pretty little heads about that! Bering tells us:
I don't know about you, but I'm riveted, and convinced, by much of the logic in this anti-rape area. And researchers are just getting started. Above is a set of astonishing truths that, had an evolutionary approach to studying complex social behavior not been adopted so rigorously over the past quarter-century and applied to human sexuality, would have gone entirely unnoticed
Truths! Astonishing truths! If nothing else, you should be alarmed by any writing which describes research findings in those terms. Or talks down to you.