In this blog post, I will summarize the debate raised by evolutionary psychology regarding whether “rape is an adaptation” and examine the major counterarguments raised in light of the definition of adaptation and its historical and social contexts.
Background of the Debate
Now, 200 years after Charles Darwin proposed the theory of biological evolution, “evolution” has become a familiar concept widely used in society. Many people have been exposed to the term “evolution” through the media since childhood, and within academia, attempts to apply the concept of evolution to various fields have continued. In particular, evolutionary psychology—which seeks to explain the human mind and behavior from an evolutionary perspective—has been actively researched since the late 20th century, giving rise to sensitive topics in the process. The question, “Is rape an adaptation?” was one of the controversies sparked by evolutionary psychology.
The debate spread after behavioral ecologist Thornhill published a book titled ‘The Natural History of Rape’. In this book, the author presented a perspective interpreting rape as a product of evolution, prompting many feminists and social scientists to raise objections. Since the concept of “evolution” carries an image of progress and naturalness, ethical concerns followed, questioning whether linking rape to evolutionary concepts amounted to justifying crime. Evolutionary psychologists explained that they were merely attempting an interpretation from a biological perspective, not advocating for rape, but the controversy continued to escalate and spread. This debate led me to the book ‘Darwin’s Table’, which was my first introduction to the topic.
The Definition of Adaptation and the Logic of Viewing Rape as an Adaptation
Before delving into the main discussion, it is necessary to clarify the precise definition of “adaptation.” ‘Darwin’s Table’ explains adaptation as a product of natural selection. Here, natural selection refers to the process by which traits advantageous in the external environment persist, while disadvantageous traits disappear. For example, a lion with claws hunts well, survives, and produces offspring, whereas a lion without claws cannot do so and thus fails to pass on its genes through generations. The key point is that there is an intermediate process—hunting—between the presence or absence of claws and environmental advantage. In other words, natural selection operates through the combination of two causal relationships: “having claws leads to better hunting” and “better hunting leads to an environmental advantage.”
Interpreting adaptation in this way, it can be defined as the process by which traits change to achieve goals that are advantageous in a given external environment. In traditional biology, traits were limited to external characteristics, but evolutionary psychology has expanded this scope to include internal characteristics. Therefore, the logic that a tendency to commit rape can also be treated as a trait holds true.
The argument that views rape as an adaptation is divided into two causal relationships. First, “Committing rape is advantageous for reproduction.” Second, “If it is advantageous for reproduction, it is advantageous for survival.” The latter is obviously true in the context of natural selection. The issue lies with the former—namely, whether rape actually increases reproductive success.
In ‘Darwin’s Table’, there is a scene where evolutionary biologists argue that factual issues and ethical issues must be separated. They explain that an evolutionary interpretation of rape does not imply ethical justification. While the distinction between facts and value judgments is theoretically valid, in reality, the public’s ethical perspective can influence factual matters. Since adaptation aims to increase survival rates in the surrounding environment, the environment surrounding humans includes social norms, public opinion, and laws and regulations. Therefore, when discussing adaptation, one cannot exclude the influence of established ethical concepts.
Counterarguments and Rebuttals Regarding the Adaptive Nature of Rape
Rape may appear advantageous for reproduction at the moment it occurs. However, numerous problems follow in its wake. In human society, women who are victims of rape suffer a heavy burden due to social scrutiny, personal ethical beliefs, and the psychological distress caused by the act of coercion. Many choose to have an abortion or suffer a miscarriage due to the stress. Even if the woman gives birth, the child born of rape is unlikely to receive a loving upbringing, and historically, illegitimate children have faced discrimination and abuse, resulting in low survival rates. Consequently, the survival rate of children born of rape is inevitably lower.
Furthermore, the perpetrator of rape is isolated from society through legal sanctions or is despised due to others’ ethical consciousness. These factors suggest that the act of rape works against reproductive success in the long term. Therefore, the claim that “rape is advantageous for reproduction” is directly refuted. From this perspective, it is more reasonable to view rape as a negative byproduct of sexual desire rather than an adaptation.
A common critique of this view points out that evolution occurs over long periods of time and argues that we must go back to primitive times when the legal and ethical regulations of modern civilization did not exist. The logic is that sexual ethics and discipline may have been weak in primitive societies, and therefore, if rape were more efficient than monogamy, a tendency toward rape would have been maintained through natural selection.
Two counterarguments can be raised against this criticism. First, for the concept of rape to exist, the victim must be able to perceive the act as wrongful. In other words, the fact that a discussion of rape is possible implies the existence of at least a minimal sense of sexual ethics; therefore, even in primitive societies, an ethical perspective cannot be completely ruled out. Second, in primitive societies, due to resource scarcity and the difficulties of survival, the survival of children during childhood depended heavily on the protection and labor of parents, particularly the paternal line. If a man did not settle in one household but instead sired offspring through rape, those offspring would inevitably receive inadequate care, lowering their chances of survival. Therefore, it cannot be concluded that rape is always advantageous for reproduction.
In this regard, examples of historical social structures with weak regulations against rape have also been cited. Abduction marriage is mentioned as such a case; reports indicate that abduction marriage exists in Kyrgyzstan both historically and currently, and that a certain percentage of marriages are conducted in this manner. Such cases appear to challenge the claim that “sexual ethics must exist for rape to exist.”
However, abduction marriages should be viewed as a special custom carried out under social norms or intra-group discipline. If rape were a true adaptation, this trait would primarily appear in individuals with low competitive advantage. This is because highly competitive individuals can produce offspring without resorting to rape. Abduction marriages in Kyrgyzstan are a special case involving social customs, making them difficult to use as typical evidence when determining whether rape is a general evolutionary adaptation. Rather, such social customs provide grounds for interpreting rape not as an adaptation, but as a byproduct of sexual desire.
To summarize the entire discussion: due to the existence of legal and ethical perspectives, it is difficult to view rape as advantageous for reproduction. Regarding the counterargument that regulations were likely lax in prehistoric times, it was rebutted that the very fact that the concept of rape exists presupposes a sense of sexual ethics; furthermore, since reproduction does not end with mere sexual intercourse but includes nurturing and protection, it is difficult to conclude that rape is advantageous. While special cases such as elopement do exist, they should be viewed as exceptions influenced by social customs and are therefore inappropriate as grounds for general adaptation theory.
Therefore, the conclusion of this discussion is that it is more valid to interpret rape as a negative byproduct resulting from a failure to control sexual desire rather than viewing it as an evolutionary adaptation.
