Evolutionary Theory of Rape Evolutionary

Evolutionary Theory of Rape

Evolutionary Psychology of Rape

According to Thornhill and Palmer, men rape for various reasons, but they conclude that "rape is, in its very essence, a sexual act." (Thornhill and Palmer). They believe that rape has evolved as a reproductive strategy, and is a natural, biological phenomenon. They support their theory with the following facts: most rape victims are women of childbearing age; some cultures treat rape as a crime against a victim's husband; rape victims suffer less distress when subjected to more violence; rape occurs in animal species; rape rarely involves gratuitous violence; married women and women of childbearing age experience more psychological distress after rape than do other women. (Thornhill and Palmer). They also attribute the academic reluctance to discuss an evolutionary basis for rape to the difference between social scientists, who think that human behavior developed arbitrarily and is simply learned behavior, and sociobiologists, who believe that human behavior is the result of psychological adaptations. Therefore, they conclude that modern rape-prevention strategies are doomed to failure because they are based on the social-science view and ignore the Darwinian theory of natural selection. (Thornhill and Palmer).

First, Thornhill and Palmer discuss gender differences. They point out that, "from a Darwinian perspective, every kind of animal...has evolved to produce healthy children that will survive to pass along their parents' genetic legacy." (Thornhill and Palmer). They believe that the differences between the sexes; the male contribution to reproduction can be limited to an act of sexual intercourse, while women had to endure pregnancy, childbirth, breastfeeding, and childrearing to ensure the survival of their genes. Therefore, women are more selective when choosing a mate, which makes mating rituals more important.

Human females are not the only ones who are selective; in fact, the males of most animal species engage in wooing and mating rituals. However, "though most male animals expend a great deal of time and energy enticing females, forced copulation, rape, also occurs, at least occasionally, in a variety of insects, birds, fishes, reptiles, amphibians, marine mammals and nonhuman primates." (Thornhill and Palmer). In fact, scorpionflies appear to have developed an organ specifically designed for rape; though they resort to rape only when they cannot obtain their traditional nuptial gift. (Thornhill and Palmer).

Thornhill and Palmer discuss rape as a reproductive strategy. Women typically chose men with symmetrical body features, or who have had greater power, wealth, or status than their rivals. Rape has evolved as an additional means for males to gain access to females; perhaps for men who were socially disenfranchised or when the social costs were low for the rape. They also discuss the possibility that rape may not have evolved as a reproductive strategy, but "as a side effect of other adaptations, such as the strong male sex drive and the male desire to mate with a variety of women." (Thornhill and Palmer). Regardless of its cause, rape has evolutionary origins, which means that men possess genes that promote rape, though they may not have evolved for that purpose. (Thornhill and Palmer).

In fact, Thornhill and Palmer suggest that the psychological pain associated with rape is linked to the fact that rape reduces reproductive success by depriving a woman of the opportunity to select her mate, and possibly threatening a woman's long-term partnership. Studies have confirmed that the more a "rape interfered with the women's reproductive interests, the more pain they felt." (Thornhill and Palmer). Women of reproductive age suffered greater distress than younger and older women, as did married women. Furthermore, penile-vaginal intercourse was more distressing to women of childbearing age. "For all those reasons, the psychological pain that rape victims suffer appears to be an evolved defense against rape," which motivated them to avoid rapes. (Thornhill and Palmer).

Jerry Coyne criticizes Thornhill and Palmer's theory, because he believes it is based on bad science. However, he does believe that, because rape is an act of sexual aggression, it lends itself to an evolutionary explanation because most evolutionists believe that both gender-based differences in sexuality and aggression have an evolutionary basis. (Coyne, p.174).

He agrees that males compete for access to females, but does not necessarily agree that rape is a product of evolution.

Coyne understands Thornhill and Palmer's by-product theory of rape evolution to mean that rape is the by-product of other traits that led to reproductive success; probably male promiscuity and aggression. (Coyne, p. 175). This accounts for rape being a sexual act, not simply an act of aggression.

Coyne does not disagree with this proposition; he simply finds it banal. He believes that all human activities can be described as by-products of evolution in some fashion, if one uses the same reasoning as Thornhill and Palmer. Furthermore, he points out that even maladaptive traits (one that do not increase the likelihood of gene transmission, like adoption) could be explained in this manner, which defeats the evolutionary question. The fact that evolution can be seen as a contributing factor to all human behavior means that Thornhill and Palmer's hypothesis is impossible to prove false, which means it is not a hypothesis, but a tautology. As a result, Coyne dismisses the by-product theory. (Coyne, p. 177).

Next, Coyne investigates the direct-selection hypothesis. This hypothesis suggests that all men are born with the capacity to rape, but that they only do so when the cost-benefit analysis favors rape. Coyne questions their supporting evidence. First, he does not believe that the fact that other species rape and have even adapted for that purpose can be extrapolated to human beings. Second, he criticizes the fact that they did not investigate the mathematics behind their hypothesis. In fact, because so many rapes are unreported, it is impossible to know if rapists actually have more children than similarly-situated non-raping males. Furthermore, it is impossible to know the reproductive costs of such rapes, versus the reproductive benefits. In addition, today's costs and benefits are irrelevant; the costs and benefits of the behavior at the time of evolution is what are important, and those are impossible to determine at this time. In fact, Coyne posits that the reproductive costs were higher for our ancestors, and that the benefits were lower, which would make it less likely that rape is an evolutionary function. (Coyne, p.179).

Coyne also investigates the technical aspects of rape to see if evolution appears to motivate rape, but draws a far-different conclusion from the evidence. Coyne believes that the fact that over one-third rape victims are not of childbearing age makes it difficult to posit rape as a reproductive strategy. (Coyne, p.180). Almost one-fifth of rape cases do not involve vaginal penetration and one-half of them do not involve ejaculation into the vagina. (Coyne, p.180). A significant number of rapes do involve more violence than required to subdue the victims. (Coyne, p.180). Furthermore, many rapes involve multiple attackers, end in the death of the victims, or involve same-sex victims; none of these features would increase a likelihood to reproduce. (Coyne, p.181).

Tooby and Cosmides believe that Coyne's criticisms were off-base and focused on attacking evolutionary psychology, rather than actually questioning the science behind Thornhill and Palmer's science. They believe that Coyne specifically misstated evidence from the book, perhaps most egregiously by characterizing both Palmer and Thornhill as believing that rape was the result of direct adaptation, when their writings clearly demonstrate that Palmer's theory is that rape is a by-product of natural selection. They disagree that unfalsifiable claims are improvable. They back up their opinion with examples:

Sufficient design evidence, as is the case with the visual system, the biochemistry of blood clotting, or celestial navigation in birds, can establish that the trait in question is an adaptation, not a by-product. Alternatively, traits might be neither adaptations nor by-products of adaptations, but evolutionary noise, such as the numerous neutral or deleterious protein variants found in organisms. So eager is Coyne to propagate the urban legend that adaptationist claims are unfalsifiable that he conceals from readers the reality that hundreds of hypotheses distinguishing these three possibilities are routinely tested every year by evolutionary biologists and evolutionary psychologists. (Tooby and Cosmides).

Tooby and Cosmides also suggest that Coyne has been deliberately misleading about the field of evolutionary biology, by omitting reference to well-respected scientists in the community and downplaying the role that evolutionary biology has played in useful biomedical efforts. He points out that evolutionary psychologists have made similar discoveries about other apparently sociological phenomenon, like spousal violence and child abuse. Finally, Coyne omitted:

Neil Malmuth's successful use of an evolutionary psychological framework to identify and empirically confirm a number of previously unknown risk-factors in the development of a sexually aggressive or sexually coercive orientation in men- that is, the tendency to commit rape." (Tooby and Cosmides).

Tooby and Cosmides use Coyne's critique as a reason to launch into the current academic political climate, which shies away from the use of evolutionary theory in any of the social sciences. They clearly advocate the use of well-established findings from evolutionary sciences to inform the social sciences. 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.