In this blog post, we will examine the debate surrounding whether rape is an adaptation—as raised in evolutionary biology and evolutionary psychology—along with the evidence supporting it, and explore how this can be interpreted from the perspectives of natural selection and reproductive strategy.
Arctic foxes living in cold regions evolved to have larger bodies and smaller ears to maintain a warm body temperature, while desert foxes living in hot regions evolved to have smaller bodies and larger ears to effectively dissipate body heat.
Initially, foxes in both regions likely had bodies and ears of moderate size. However, even within each population, some foxes would have been larger than others, while others would have been smaller. In cold environments, larger foxes found it easier to maintain their body temperature, giving them a survival advantage over smaller individuals; conversely, in hot environments, smaller foxes had the survival advantage. Individuals with a survival advantage are more likely to survive long enough to reproduce than those without, so they naturally gain an advantage in reproduction as well.
If these body size traits are passed down to the next generation, over a long period of time, foxes with body sizes suited to that environment will survive, while those that are not will gradually disappear. This is called “evolution by natural selection,” and the traits formed as a result of natural selection are called “adaptations.”
Evolutionary biologists have sought to explain the diverse behavioral patterns of humans and animals through these concepts of natural selection and adaptation. However, this interpretation does not always garner the consensus of all researchers. ‘Darwin’s Table’ focuses on the highly sensitive topic of “rape” and introduces the debate among evolutionary biologists regarding whether rape is an evolutionary adaptation or not.
In ‘Darwin’s Table’, Cosmedis references Randy Thornhill’s book ‘A Natural History of Rape’ and suggests the possibility that rape is a behavior shaped by natural selection over a long evolutionary process. According to his explanation, rape is one of the behaviors through which some men who struggle to find mates increase their chances of passing on their genes to the next generation. In other words, it can be interpreted as an adaptive behavior that evolved to increase reproductive success in environments where reproduction is difficult. Steven Pinker also expressed some agreement with this perspective.
Jerry Coyne, on the other hand, opposes this argument. While Thornhill cited the fact that most rape victims are young women of childbearing age as evidence for this adaptive explanation, Coyne points out, based on various research findings, that this explanation alone is insufficient. He also emphasizes that there are cases where reproductive status alone cannot adequately explain rape behavior. Furthermore, Stephen Jay Gould raised the question of whether cases such as male-on-male rape, incest, and sexual crimes against children can be explained solely by the goal of reproduction.
I believe that rape can be explained to some extent from an evolutionary psychological perspective. However, this does not mean justifying or ethically defending rape; rather, it involves examining the evolutionary context in which such behavior has been discussed.
According to Richard Dawkins’ ‘The Selfish Gene’, the behavior of all living organisms can be understood from the perspective of the survival and transmission of genes. The explanation is that genes influence the behavior of living organisms in order to pass themselves on to the next generation.
Men and women incur different biological costs in the reproductive process. Generally, men incur relatively low biological costs in providing sperm, whereas women make a much greater biological investment in pregnancy, childbirth, and, in the case of mammals, the early stages of parenting. Because of these differences, evolutionary psychology has suggested the possibility that men and women have developed different reproductive strategies.
From this perspective, it is suggested that natural selection may have shaped strategies in which men seek to secure as many reproductive opportunities as possible, while women tend to be more selective in choosing their reproductive partners.
Therefore, if reproductive strategies differ, some men may struggle to reproduce because they are outcompeted in the process of securing a mate. To explain this situation, some evolutionary psychologists argue that even extreme behaviors can be discussed within an evolutionary context. However, modern evolutionary biology does not view specific behaviors as being determined by a single “rape gene.” Human behavior is understood to arise from the complex interaction of numerous genes, environmental factors, and sociocultural influences; attributing specific criminal behavior to a single gene is inconsistent with current scientific evidence.
Nevertheless, some researchers are exploring what selective pressures extreme sexual coercive behavior may have been associated with during human evolution, while clearly distinguishing that these discussions are merely scientific attempts to explain the causes of such behavior—not arguments intended to justify or condone it.
Because reproductive strategies differ, some men who are at a competitive disadvantage may struggle to secure a mate. To explain this situation, some evolutionary psychologists argue that extreme sexually coercive behavior can also be discussed within an evolutionary context. However, modern evolutionary biology and behavioral genetics do not view specific behaviors as being determined by a single gene. Human behavior is understood as the result of the complex interplay of numerous genes, an individual’s developmental history, sociocultural environment, and psychological factors.
Therefore, there is currently insufficient scientific evidence to conclusively assert—as some past studies have suggested—that a specific “rape gene” exists and has become universally widespread through natural selection. Contemporary research explains that such behavior arises from the interaction of various biological and environmental factors, rather than from a single cause. However, some evolutionary psychologists are exploring the possibility that extreme sexually coercive behavior may have emerged under certain evolutionary selective pressures; they make it clear that this discussion is merely a scientific attempt to explain the origins of the behavior and does not justify or condone it.
Regarding the claim that rape is an evolutionary adaptation, Stephen Jay Gould raised the question of how to explain cases of men raping other men or sexual crimes against children. He argued that since these cases cannot lead to reproduction, they are difficult to explain solely through reproductive strategy.
In response, I believe these cases should be examined separately rather than interpreted within the same category. While sexual violence against fertile women, sexual violence between same-sex partners, and sexual crimes against children are all crimes in the same sense, the possibility that different factors may have been at play must be considered when attempting an evolutionary biological explanation.
The opposite of rape can generally be viewed as consensual sexual relations. Sexual behavior between a man and a fertile woman has the potential to result in biological reproduction. In contrast, same-sex sexual behavior or sexual crimes against children are not directly related to reproduction; therefore, there are limitations to understanding them through the same evolutionary explanation alone.
Therefore, while sexual violence against women of childbearing age and sexual violence against men or children share the same ethical and legal nature as criminal acts, I believe they must be approached as distinct issues when examining evolutionary biological hypotheses. Just as whales and sharks are similar in appearance but whales are mammals and sharks are fish, phenomena that appear similar on the surface may have different origins and require different explanations.
However, there is also a counterargument that since rape of women of childbearing age and sexual violence against men or children are both behaviors stemming from sexual desire, they should ultimately be viewed as the same phenomenon. This position aligns with the argument that rape is not a behavior for reproduction but rather the result of an excessive expression of sexual desire—and is ultimately a byproduct of sexual desire.
However, this explanation alone is insufficient to fully account for human reproductive behavior as a whole. If all sexual behavior were simply a byproduct of sexual desire, consensual sex could also be interpreted in the same way. In other words, this raises the problem that reproductive behavior itself would have to be explained as merely a result accidentally produced by sexual desire.
However, human sexual behavior is highly diverse, and not all actions taken to satisfy sexual desire lead to reproduction. Therefore, it can be argued that understanding reproductive behavior solely as a byproduct of sexual desire lacks explanatory power. Evolutionary biology suggests the possibility that not only sexual desire itself but also the selective pressure to pass one’s genes on to the next generation through reproduction may have acted in tandem.
From this perspective, while sexual desire may be one of the key motivations driving reproductive behavior, there are limitations to categorically asserting that all reproductive behavior is merely a byproduct of sexual desire. Consequently, some evolutionary psychologists have attempted to understand rape within the context of reproductive strategy and natural selection, rather than explaining it solely through sexual desire. Of course, this explanation is merely a hypothesis intended to explore the evolutionary origins of behavior and is distinct from the fact that rape is a serious crime in modern society.
Randy Thornhill, author of ‘The Natural History of Rape’, has faced significant criticism since the book’s publication; in particular, some have strongly objected on the grounds that his research could be misinterpreted as justifying rape. In fact, the rape adaptation hypothesis proposed by evolutionary psychology has remained one of the most controversial topics in academia from the time of its introduction to the present. Even today, support and criticism coexist, and neither side’s view is accepted as the established consensus.
What is clear is that rape is a serious crime in any society, including South Korea, and that any sexual act committed against the victim’s will can never be justified, either ethically or legally. The fact that evolutionary biology or evolutionary psychology studies the origins of such behavior does not mean that the behavior itself is justified or condoned.
Rather, exploring the causes of human behavior from various academic perspectives to better understand it is one of the important roles of science. Just as numerous human behaviors—such as aggression, cooperation, altruism, competition, and parental care—have been the subject of research in evolutionary biology, research can also be conducted to analyze the origins of sexual violence as a type of human behavior.
However, such research is intended solely to explain the causes of behavior and does not replace social responsibility or moral judgment. This is because scientifically explaining the causes of behavior and evaluating the ethical value of that behavior are issues on different planes.
I believe that the act of rape can be explained to some extent from the perspective of natural selection and reproductive strategies. However, considering the findings of modern evolutionary biology, it is difficult to explain this phenomenon solely through a single gene or a single adaptive strategy. Human behavior arises from the complex interplay of biological, psychological, sociocultural, and environmental factors; therefore, research from various academic disciplines must be considered together.
Ultimately, the debate over whether rape is an evolutionary adaptation or a byproduct of other adaptations remains an ongoing academic topic. The important point is that the purpose of this discussion is not to justify crime, but rather to gain a deeper understanding of the origins of human behavior and, furthermore, to seek scientific and social approaches that can prevent and reduce sexual violence.
