Sociobiological theories of rape are theories that posit that, by studying animal and plant sexual behaviors, rape by humans can be explained as a biological drive for genetic fitness. but also to insects and flowers. In so doing, he conflates the highly rigid courtship dances of insects with human relationship norms, such as dating. Hummingbirds also have a mating ritual involving the exchange of food to the female. Larry Wolf, calls the females of hummingbirds "prostitutes" for accepting this exchange even outside their fertile window, but do not call them "prostitutes" if they do so during their mating season. Critics have pointed so that, by following this logic, a human prostitute would not be considered so if they got pregnant during their services.

McKibbin et al. (2008) argue that there may be several different types of rapists or rape strategies. One is rape by disadvantaged men who cannot get sex otherwise. Another is "specialized rapists" who are more sexually aroused from rape than from consensual sex. A third type is opportunistic rapists who switch between forced and consensual sex depending on circumstances. A fourth type is psychopathic rapists. A fifth type is partner rape due to sperm competition when the male suspects or knows that the female has had sex with another male. There are varying degrees of empirical support for the existence of each of these types. More generally they mention research finding that at least one-third of males "admit they would rape under specific conditions" and that other surveys find that many men state having coercive sexual fantasies. They, as have others, "propose that rape is a conditional strategy that may potentially be deployed by any man." Studies have also found that sensitivity for potential coercive behaviors in males as well as handgrip strength (but only in a simulated coercive situation) increase during the fertile phase of the menstrual cycle.

Naturalistic fallacy

Thornhill and Palmer write that "Rape is viewed as a natural, biological phenomenon that is a product of the human evolutionary heritage". They further state that by categorizing a behavior as "natural" and "biological" they do not in any way mean to imply that the behavior is justified or even inevitable. "Biological" means "of or pertaining to life," so the word applies to every human feature and behavior. But to infer from that, as many critics assert that Thornhill and Palmer do, that what is biological is somehow right or good, would be to fall into the so-called appeal to nature. They make a comparison to "natural disasters as epidemics, floods and tornadoes". This shows that what can be found in nature is not always good and that measures should be and are taken against natural phenomena. They further argue that a good knowledge of the causes of rape, including evolutionary ones, are necessary in order to develop effective preventive measures.

Evolutionary psychologists McKibbin et al. argue that the claim that evolutionary theories are justifying rape is a fallacy in the same way that it would be a fallacy to accuse scientists doing research on the causes of cancer that they are justifying cancer. Instead, they say that understanding the causes of rape may help create preventive measures.

Wilson et al. (2003) argue that evolutionary psychologists like Thornhill and Palmer use the naturalistic fallacy inappropriately to forestall legitimate discussion about the ethical implications of their theory. According to Thornhill and Palmer, a naturalistic fallacy is to infer ethical conclusions (e.g., rape is good) from (true or false) statements of fact (e.g., rape is natural). Wilson et al. point out that combining a factual statement with an ethical statement to derive an ethical conclusion is standard ethical reasoning, not a naturalistic fallacy, because the moral judgment is not deduced exclusively from the factual statement. They further argue that if one combines Thornhill and Palmer's factual premise that rape increases the fitness of a woman's offspring with the ethical premise that it is right to increase fitness of offspring, the resulting deductively valid conclusion is that rape has also positive effects and that its ethical status is ambiguous. Wilson et al. state that Thornhill and Palmer dismiss all ethical objections with the phrase 'naturalistic fallacy' although "it is Thornhill and Palmer who are thinking fallaciously by using the naturalistic fallacy in this way".

Preventing rape

Thornhill and Palmer (2000) suggest a number of possible strategies for preventing rape. One example is explaining to males that they may have predispositions to misread the female invitation of sex. They believe that viewing rape as being due to a desire for domination, and not related to sexual desire, is generally harmful. One example given is the claim that the way women dress will not affect the risk of rape. They argue that the much greater societal freedom of dating without supervision, and removal of many barriers between males and females, have created an environment that has also removed many earlier societal controls against rape. It is recommended that "men and women interact only in public places during the early stages of their relationships". Palmer and Thornhill responded to these critics in an article in the journal Evolutionary Psychology.

Smith et al. (2001) criticized Thornhill and Palmer's hypothesis that a predisposition to rape in certain circumstances is an evolved psychological adaptation. They developed a fitness cost/benefit mathematical model and populated it with estimates of certain parameters (some parameter estimates were based on studies of the Aché in Paraguay). Their model suggested that generally only men with a future reproductive value of one-tenth or less of a typical 25-year-old man would have a net positive cost/benefit fitness ratio from committing rape. On the basis of their model and parameter estimates, they suggested that this would make it unlikely that rape generally would have net fitness benefits for most men.

While defending the evolutionary psychology theory of rape against its more vehement critics, Vandermassen (2010) provides a critique of some aspects of the view. She characterises the view of Thornhill and Palmer as "extreme" (p. 736), as they fail to allow for the influence of any non-sexual motivations in the crime of rape. Vandermassen also notes two problems with the data cited by Thornhill and Palmer regarding the psychological trauma caused by the violence associated with rape: firstly, the data is inaccurately and confusingly presented in the book, often obscuring the fact that they do not support Thornhill and Palmer's "counterintuitive hypothesis" (p. 744) that more physical violence during rape is associated with less psychological pain. Secondly, more recent research has failed to support this hypothesis. A more moderate position, integrating the evolutionary psychology and feminist theories on rape, is presented by Vandermassen, based in part on the work of feminist evolutionary researcher Barbara Smuts.

Hamilton (2008) has criticized Thornhill and Palmer's definition of rape as the coerced vaginal penetration of women of reproductive age. He has suggested that the exclusion of male rape, rape of women outside the reproductive age range, murderous rape, and non-vaginal forms of rape virtually guaranteed the confirmation of their hypothesis that rape is an evolved reproductive strategy and not a crime of violence. Hamilton has argued that evolutionary psychology fails to explain rape because, by evolutionary psychology's own criteria, an adaptation to rape children or men, or non-vaginal rape, would have been eliminated in the course of evolution because it did not confer reproductive advantage on our ancestors.

Evolutionary psychologist David Buss states that clear-cut evidence for or against rape as an adaptation is lacking. He states that rape may instead be a non-adaptive by-product of other evolved mechanisms, such as desire for sexual variety and for sex without investment, sensitivity to sexual opportunities, and a general capacity for physical aggression.

See also

  • Anthropomorphism
  • Animal sexual behaviour: coercive sex
  • Sexual selection
  • Violence against women

References

  • The Evolutionary Psychology FAQ entry on rape
  • Insult to injury 20 June 2001 New Scientist Print Edition by Matt Walker
  • Link between rape and pregnancy 20 June 2001 BBC News.