In a recent class discussion a debate brewed over the topic of Randy Thornhill’s and Craig Palmer’s A Natural History of Rape. The arguments proposed in their book have been widely criticized and rejected by much of the scientific and philosophical community (for good and bad reasons). What follows is some general thoughts; perhaps though, a formal paper will emerge for this topic if a good discussion results. It seems there are some important flaws that can be revealed in the assumptions Thornhill and Palmer use to make their argument. I am inclined to use an example from the history of evolutionary biology, namely, Stephen Jay Gould’s criticism of the assumptions underlying the adaptation of antlers in “Irish Elk.” Similar to Gould, I will reveal a similar ‘bad’ assumption that Thornhill and Palmer use and then present an alternative argument that may prove more convincing.
Recall that the assumptions the adaptationist program was using to explain the immense antlers (and bodies) of the Megloceros, or “Irish Elk,” focused on combating predation where antlers served as weapons. However, the largest predator that this creature would ever face in the late Irish Pleistocene was a wolf pack. In fact, these massive antlers could be harmful to the survival of the Elk. That the antlers were often detrimental to the survival of the Elk seemed to present and anomaly for Darwin’s theory of natural selection, as a trait was being selected for that was harmful to the individual. It was Gould who pointed to the faulty assumption that antlers were weapons combating predators and that this was the only way large antlers would emerge. Gould challenged this assumption and insisted that competition for females may have led to large bodies. That is, Elk with larger body size would tend to triumph over those males who were smaller ultimately leading them to pass their genes on to offspring. A consequence of this, of course, are larger antlers; this follows a principle of allometry.
Likewise, it is my contention that Thornhill and Palmer use a faulty evolutionary assumption, that rape is intended for procreation. There are at least two general categories that we can place rape in: (1) genetically predisposed (I am not suggesting a ‘rape gene’, rather just that there could exist genes that when malfunctioning or ‘overly present’ may create an anxious and violent drive for sex leading to something such as rape) and (2) conditionally predisposed (e.g., watching violent pornography may construct an anxious and violent cognitive drive for sex). (1) is where Thornhill and Palmer would need to focus there argument, as individuals regarding (2) could not pass their traits on to their offspring, or at least not genetically. Further, the argument that Thornhill and Palmer would need to insist upon would be similar to Gould’s—that rape isn’t being selected for per se. Rather, genes correlated with behaviors of dominance (perhaps testosterone genes) are selected for via sexual selection. Suppose that in early hominins males with higher levels of testosterone are selected for because they can dominant their opponents for mates (not a surprising behavior among apes). These individuals will pass their genes on to their offspring who in turn compete for mates and pass their genes on. What tends to emerge are males with aggressive behavior causing genes. Since these genes will also correlate with sex drives, then a by-product—an unfortunate one in this case—emerges where individuals with increased aggressive and sexual drives may ‘rape’ other members in the population. That “rape is selectively advantageous for procreation” can be rejected in the same fashion that the original argument used in Megaloceros’ antlers was rejected.