In this blog post, we will examine the debate over whether rape is a biological adaptation or a byproduct of distorted sexual desire from biological, psychological, and social perspectives.
In a group with various variations, when a specific variation (trait) is more suitable for the environment than others, individuals with that trait have an advantage in survival. This phenomenon is a common form of evolution in nature. For example, just as animals that evolved thorns as weapons in areas with many thorny trees have higher survival rates, traits adapted to the environment greatly influence the survival and reproduction of individuals. If these traits are hereditary, they are passed down through generations and become established as general characteristics of the group. This is what Darwin referred to as natural selection. Natural selection is one of the core principles of biological evolution and an important concept that explains how organisms adapt to their environment. Scholars refer to the products of natural selection as “adaptations.”
Behavioral ecologist Shonhill’s “The Natural History of Rape: The Biological Basis of Sexual Coercion” sparked a debate over whether rape is indeed an adaptation. This debate is divided into two camps. One side consists of adaptationists who argue that rape is an adaptation, while the other side consists of anti-adaptationists who view rape as a byproduct of sexual desire. This debate has sparked deep discussions on various aspects beyond the biological evolution of organisms, including human morality, ethics, and social behavior patterns.
The adaptationists’ argument is as follows: They argue that since the victims are primarily women of childbearing age, men who face difficulties in reproduction engage in rape. Therefore, rape is an adaptive behavior that helps men succeed more in reproduction, and it is fundamentally closer to sexual behavior than violent behavior. Calling rape an adaptation does not mean it is inevitable or ethically correct. It is merely a matter of fact. They further support the legitimacy of rape by pointing out that male insects of the genus “parasitoids” have adapted physical structures specialized for rape. In addition to the example of insects, they present various other cases in the animal kingdom that exhibit similar behaviors to reinforce the claim that rape is the result of natural selection.
Anti-adaptationists call evolutionary biology, which they believe too easily produces adaptations, the “adaptationist program,” and mock adaptationists for seeing everything as an adaptation. They refute Shonhill’s book and the arguments of adaptationists. They cite the fact that most victims are women of childbearing age, between 12 and 44 years old, as evidence. They argue that this is because physically attractive people are more likely to be targeted. Rape offenders do not act for the purpose of reproduction. While some sex offenders commit crimes to achieve sexual satisfaction, the primary motive for rape is often not sexual satisfaction. Dominance and anger are more likely to be the primary motives. Additionally, according to the book, 30% of victims are children under the age of 12, and there is no way to explain this.
To explain extreme behaviors like rape, we need to look beyond biological factors and consider psychological and social factors as well. Rape offenders often exhibit abnormal psychological states. They tend to have low self-esteem, distorted thoughts about sexuality, and a lack of understanding of others’ boundaries. Rape offenders can be broadly categorized into four types. First, there are those who want to prove their power, second, those who want to see their victims cower in fear, third, those who want to vent their feelings of inferiority and anger toward women through violence, and fourth, those who enjoy seeing their victims suffer. Based on this, it is impossible to conclude that normal men never commit rape, but it is possible to infer that rapists are not normal. Therefore, it is difficult to view rape as a natural result of evolution for reproduction. In the words of the book, rape is merely a byproduct of sexual desire expressed in a distorted manner.
Sexual behavior can take various forms. Consensual heterosexual intercourse and masturbation are representative examples. Among these, only a very small portion of consensual heterosexual intercourse is aimed at reproduction. In this sense, rape can also be considered one of the various forms of sexual behavior. However, this judgment is based solely on sexual desire. Rape is a secondary phenomenon that occurs when various psychological and mental factors are added to sexual desire.
In response to this, it can be argued that although rape is an action caused by “sexual desire + α,” its essential purpose is the realization of sexual desire, and the remaining psychological factors are selection mechanisms. However, these additional psychological factors are not beneficial for survival. Therefore, even if their argument is correct, the act of rape, which is influenced by these factors, cannot be considered adaptation. Rather, rape has a negative impact on offspring. While it may slightly increase the likelihood of spreading one’s genes, this is particularly irrelevant in modern times, as it does not contribute to perpetuating one’s lineage. According to the book Freakonomics, legalizing abortion and preventing unwanted births has greatly contributed to reducing crime rates. Women who become pregnant through rape end up with unwanted children. Therefore, these children are unlikely to be raised successfully. This may be true for animals, but humans are distinctly different. We are not merely tasked with spreading our genes; we must raise our offspring to become successful members of society. Human society has complex social structures and norms, so behavior that focuses solely on reproduction can actually have the opposite effect. It is difficult to understand the argument that reproduction is the sole purpose of life, as it is for animals.
Thus, the debate over whether rape is an evolutionary adaptation goes beyond a purely biological perspective and highlights the complex nature of the issue, which must consider moral, ethical, and social factors. Therefore, when addressing such issues, it is essential to adopt a multifaceted approach.
