They accuse Coyne of giving modern intellectuals "permission to remain biologically illiterate, through assuring them there is nothing useful or important that they could learn that would help them address the intellectual problems they face." (Tooby and Cosmides).
Without undertaking an independent investigation of the evidence used to support each author's work, it is impossible to determine who makes the most valid arguments. However, if the facts listed argued by Tooby and Cosmides are true, then they do much to bolster the arguments made by Thornhill and Palmer. In fact, the arguments made by Thornhill and Palmer are very sound from a logical point-of-view, even if it is ultimately impossible to prove or disprove their hypothesis. That at least one species of animal has evolved a special organ specifically to accomplish rape clearly establishes that rape can be an evolutionary function and can be related to genetic evolutionary success. Furthermore, they do not focus on the motives of modern rapists, but instead on what type of behavior may have led to the selection of genes that would promote raping behavior. If reproductive age women and disenfranchised men are overrepresented as rape victims and rapists, those factors would seem to support an evolutionary element to rape.
The aspect of Coyne's argument that appeared the weakest was his due focus on child molestation and homosexual rape. For a man, the act of having sex with a child or with another man is, by definition, maladaptive sexual behavior, because it is impossible for such sex to result in the transmission of genes. Therefore, to use the fact that both children and males are highly represented among rape victims to disprove the concept that rape behavior is the result of evolution is irresponsible science. Consensual homosexual sex is maladaptive sexual behavior, and the gene for homosexuality, if there is one, is not represented in a significant portion of the population. However, the rape gene, if there is one, would have to be highly represented in society, since the percentage of men who have forced sexual contact on a partner is much higher than the percentage of men who have engaged in consensual homosexual contact. Therefore, it is clear that these genes are not the same genes; as a result, one could be homosexual and still carry a gene that combines violence with sexuality. However, one's homosexual orientation would naturally translate that impulse to homosexuals. The same argument could be made for child molestation. Coyne's failure to acknowledge that possibility is his greatest weakness.
Coyne also posits that the reproductive costs of rape would be so high in evolving societies that it would argue against an evolutionary theory of rape. However, the sociological evidence does not tend to support such a theory. In every historical society, it has been women who bear the social costs of rape, making later reproductive success less likely for them, but not for the rapist. While individual families or victims may have sought retribution, it is only in the last 100 years or so that any society has taken a hard-line view of rape as a crime and supported harsh penalties against the rapist. To assume otherwise in developing societies is not supported by looking at primates who rape; male primates are not punished for sexually aggressive behavior.
Given that there has not been one human society that does not engage in rape, and that rape is almost exclusively perpetrated by males, it seems entirely possible that men are genetically predisposed towards rape, given the appropriate triggering conditions. That modern societies see large epidemics of rape in war-time or under conditions like slavery or the modern sex-trade, it seems equally clear that one of those triggering factors if viewing the potential victim as something slightly less than human. In addition, given that rape is used as a wartime weapon for the stated purposes of "ethnic cleansing" it is clear that some rape is used reproductively. Furthermore, none of the researchers discusses the phenomenon of spousal rape, which is extremely prevalent, typically not-reported, not a crime in the majority of countries, and frequently results in pregnancy.
Coyne, Jerry. "Of Vice and Men: A Case Study in Evolutionary Psychology." The University of Denver Portfolio Community. 2007. The University of Denver. 12 Feb. 2008 https://portfolio.du.edu/portfolio/getportfoliofile?uid=98279.
Thornhill, Randy and Craig T. Palmer. "Why Men Rape." Iranscope.com. 2000. Iran Scope.
Tooby, John and Leda Cosmides. "Letter to the Editor of the New Republic." The University of Denver Portfolio Community. 2007. The University of Denver. 12 Feb. 2008 https://portfolio.du.edu/portfolio/getportfoliofile?uid=98280.