A Natural History of Rape?

Hey guys sorry about the long pause, funny how when you have nothing to do you do nothing and when you have too much to do you get it all done. I have dug up some of the research talked about here that isn’t really available through normal lit searches. I have the Gotschall study on rape pregnancy frequency in PDF and another article by Gotschall that I will be talking about a little in this post about rape and war and a break down of his version of the pro/cons of the different rape hypothesis. If someone wants to look at these papers and since the first one I can’t find in any lit search and the second on is in-press I am sure I can e-mail you the relevant parts. So with that out of the way on with the show.The first thing I want to address is the idea that I have seen pop up in two different post. This is the idea that rape has to have some sort of advantage to the female and if it does not it destroys the rape adaptation hypothesis. This is completely false. The rape adaptation hypothesis says out right that rape is NOT a benefit to the female. What you have to realize is that evolution and evolutionary psychology (in particular reference to humans) sees female choice as one of the defining aspects of selection. The ability for a female to choose who will father her offspring is the source of a GREAT deal of sexual selection. Vast branches of evolution have been built on male competition to have the right and even larger branches have been built on females developing some extraordinary means of controlling both mating and even ejaculates. Females are evolved to desire this choice above all else. Those females that were very choosy about those partners who would father there children would do significantly better than those that simply wanted children by anyone around. In humans this is even more salient. With a minimum of probably 4-5 years of investment in each offspring and a very small number of offspring per pregnancy the need to pick high quality is easily apparent. This means that rape does NOT offer an advantage to women and is a serious cost. It is this cost that has lead to predictions about the kind of trauma women will experience in rape. A huge portion of Thornhill’s research has been in the avenue of predicting what type of rape will produce the greatest trauma under which circumstances. The predictions of course are built on the ideas of this choice cost analysis. The second point is that rape being a cost to the female some how shoots down this view. For something to evolve it does not have to offer equal benefits to both sexes. Cryptic ovulation cycles in women might be a good example of this. By hiding when she is most likely to become pregnant a women gains a significant advantage with the use of extended sexuality to keep men bonded to her. But this cryptic cycle is not a benefit to the male which has no idea when he is likely to get his mate pregnant.I have been asked to talk about what rape would look like if it was not an adaptation. Let me try an analogy. What if I were to make the claim that the use of paper currency is a psychological adaptation for resource management? What kind of problems would I have in making this claim? I see the following: first it is an evolutionarily novel phenomenon and therefore there has been no time for it to be selected for, second there is no evolutionary history of it emerging before this is not that significant but if there was truly an advantage to it I would expect maybe to seem something somewhat analogous in other species if nothing less than maybe some simpler versions that could have been used as fodder for selection, third the use of paper currency over any other economic system doesn’t seem to offer a specific reproductive or survival benefit to anyone, and finally the BIG one the use of paper currency or any other type of currency fluctuates HUGELY both in history and across cultures. So how might this apply to rape as not an adaptation? Well rape is clearly not a novel phenomenon it has been around for millions of years, you can see it most of the primate family and in many other species. This is big, many species that have no cultural as we know it exhibit the use of rape under certain circumstances. It is clearly different than humans but there is analogous nature to it. If rape had a prohibitably high cost or the cost were completely ignored it could not be the function of selection. But the REALLY big on here is that I would NOT expect rape to be in every society in every time through out history and for it to be so similar in how it manifests itself. I would expect to see at least ONE culture where rape did not occur, or even one culture that did not focus rape primarily on reproductive age females. I would also not expect to see rape follow biological logic in who rapes and who does not rape and who is selected for rape. If it was cultural only I would expect to see some place where maybe women raped or that victims were of ages not evolutionarily associated with fertility. It was mentioned that the fact that women don’t rape is a problem for this theory. To me this is ridiculous. See the above paragraph for more in depth but it comes down to the simple idea that men have an incredibly small minimum investment they have to make in making a child (about two tablespoons of protein) while women have 4 years of high investment. Men are designed to inseminate when ever the chance presents itself while women are designed to be extremely choosey.I want to add a little personal note on the issue about my claim in the Gotschall study on rape pregnancy about women wanting to get pregnant the claim was based on something Gotschall had said in an interview, I should not have said it because he did not do the statistical analysis to show it. But he said it because many of the women in the one-night stand voluntary condition said they were not using birth control on purpose and would not mind a pregnancy. It was both of us probably being too loose with our rhetoric. But I don’t think it is important so I guess we should move on. I think the point remains that an 8% pregnancy rate is more than enough to provide enough fodder for selection. The question proposed is how this choice gets passed down. I am going to say right out that I don’t know. But I am also going to say that a whole lot of traits that are obviously evolutionarily selected we can’t claim to really know how they are inherited. We think it’s in the genes but how much of it is in genes what is the effect of epigenetic, embryological development, hormones, ect is still unknown and being argued about. I don’t think we have a clear blue print for how any complex trait has been inherited. To stay in this same vein of thought I want to talk about Estrous. The previous poster mentioned the idea that women do not have an estrous period. Well new research seems to suggest otherwise. During the fertility window right before ovulation women develop all kinds of interesting traits that attract them to men with good genes. My personal favorite is that women during this window can actually smell how symmetrical a guy is. Also the big finding is that women drastically increase the frequency of extra-pair copulations during this period. There defiantly seems to be an estrous effect here. The extended sexuality of women seems to be focused on long term partners with high investment and good parental skills while the estrous sexuality seems to be related to good genes. Since even the effect of an estrous period on women was thought to not exist I don’t see how this is cultural. This is a highly complex, highly condition dependent sexual strategy. Rape seems rather simple in comparison. I think there is strong evidence that both of these strategies are evolutionary adaptations, and how they get inherited to me is one of the important questions to ask in the coming decades about evolution in general and human evolution inparticular.Now on to rape and war, Gotschall in his study sites a few examples of reported rape during world war II. These numbers are likely to be undervalued but the estimates range from 20,000 to as high as 100,000 with in a few week period. The over all estimates of the Red Army rapes in Berlin climb as high as 1,000,000. I found one statistic that says there is probably 100,000-200,000 reported rapes a year in the United States. Rape in war is a common theme and it seems that these rape frequencies dwarf normal rape frequencies. Also another somewhat different example is the Yanomamo Indians in south America were documented to perform raids into other villages. One of the main goals of these raids was to rape and steal women. It was reported that almost every single women in the Yanomamo tribes had been raped at least once during these raids/wars. So what’s the point of all this? Well the main point I am trying to bring up is that it appears those people capable of rape is not limited to a select sick few. Normal men who go to war will rape when they would never think about it at home. A lot of hunter-gather cultures and cultures during wars have out-group rules that allow for or look the other way when a solider rapes a woman during conflict. This is an example of where the normal costs of the rape are eliminated. Under these conditions it appears that vast array of people are capable of rape. This something else that I find interesting in regards to what rape would look like if it was not an adaptation. The fact that it appears that most men are capable of rape (other studies have measured sexual arousal in relation to watching movies of consensual vs. nonconsensual sex scenes and found no difference) would be something I would not expect (especially cross-culturally) if rape was purely cultural.

Since I asked I'm going to address some of your points. I don't see how that follows. Firstly, straight men's sexual desire is primarily for reproductive age females. In a human world where rape was not evolutionary but sexual desire obviously was, you would still see rape, when it was perpetrated, perpetrated on reproducive age females because that's what your average rapist, being a man, would be attracted to. Likewise I would expect that, because I would expect to see rapists selecting victims by the same criteria that men select mates, i.e. biological logic. Both of these things happen. Some women are rapists. Some women outside of reproductive age are raped. Not sure what you're looking for, here.So, that's pretty much it. A world where rape is evolutionary looks exactly the same to me as a world where rape is not evolutionary, but merely an expression of violence through the vocabulary of a man's sexual desires (which are themselves evolutionary as well as cultural.) You mention situations where women were taken - were other things taken? Did looting occur? Did rape ever occur in the absence of looting?I submit that the occurance of war rape is not an evolutionary function but rather a consequnce of a greater "free-for-all" attitude prevalent in the lawlessnes following war. It's exactly what I would expect if it were cultural, and exactly what I would not expect if there were a rape gene that was only slightly selected for.Also, as an aside - you keep mentioning the universality of a trait or behavior (rape, in this case) as evidence that it is not cultural. I don't believe that's true. There are many cultural universals because the purpose of culture is always the same, everywhere that there is culture.

So why the quick dismissal that it benefits the female? There are at least a couple of roads open. Trauma to the individual doesn't preclude adaptation. There's plenty of mating trauma in the animal world.Thornhill and Palmer are apparently a bit, uh, cagey, about the whole notion of adaptation. In a review of the book Jerry A. Coyne and Andrew Berry note, "The authors lay out two alternative evolutionary hypotheses: rape is either a "specific adaptation" (i.e., natural selection explicitly promoted the act) or a "by-product of evolution" (i.e., there was no direct selection for rape; rather it is an accidental product of selection for, say, male promiscuity and aggression)."They call the second definition "meaningless". Even assuming it actually describes something which is occurring, "rape" could not be considered an adaptation, because it is not the trait being selected. But if we allow it, in whatever fashion, what grounds are there to state that the adaptation centers on the male? If rape results in higher pregnancy rates, then it seems you have two possible explanations. One, that male rapists are better sexual competitors, and the other, that physical trauma enhances fertility in the female.So why the quick dismissal? Because it's a sociological argument using a claim about a reproductive strategy as "evolutionary" evidence, not an examination of adaptation. Claiming there's an evolutionary determinant for rape sells books to people who want to see you score points off feminists. Asking whether rape might make women more fertile will get you run out of town on a rail, assuming you live long enough to be hoisted onto one.But if we don't want to talk about a possible adaptive advantage to the female, let's talk about what makes rapists better sexual competitors. Actually, let's stand it on its head--what makes better sexual competitors rapists? Because the argument isn't that rapists have twice as many opportunities to impregnate females, it's that they're twice as likely to do so. So why is it that these virile studs are shut out of the mating game in the first place? How is that adaptive? There may be other species where rape is a reproductive strategy, but are there any where the outsiders are twice as fit? Here selection seems to be working to level the playing field instead of improving the chances of survival.I'm just a withered dilettante with a habit of delayed judgement, but when I see claims of universal biological imperatives based on 405 telephone calls, I generally let the bandwagon take another loop without me.