In this blog post, we will examine the concept of adaptation, starting from Darwin’s theory of natural selection, to explore whether rape can be viewed as an evolutionary adaptation, drawing on historical and contemporary examples as well as academic debates.
Basic Concepts of Adaptation and Natural Selection
The concept of adaptation has become central to biology following the publication of Charles Darwin’s ‘On the Origin of Species’ in 1859 and has evolved alongside the field. Through his “tree of life,” Darwin posited that species do not form a hierarchical hierarchy but rather branch out and evolve into new forms, identifying natural selection as the key driving force behind this diversification. Natural selection is the process by which individuals with traits better suited to their environment survive and pass those traits on to their offspring.
When, as a result of natural selection, a trait becomes fixed and the resulting form is reproductively distinct from the original species, this is called an adaptation. However, not all biologists accept natural selection in the same way. The position that strongly emphasizes the influence of natural selection is called adaptationism, while the view that some traits may be byproducts of other evolutionary processes rather than direct results of natural selection is called anti-adaptationism.
Anti-adaptationists cite the architectural term “spandrel” as an example, emphasizing that a structure can be an accidental byproduct resulting from another structure. This term was later adopted in biology to describe byproducts arising from the evolution of other traits.
Academic Debate Surrounding Rape
Whether rape is an evolutionary adaptation is one of the most contentious topics between adaptationists and anti-adaptationists. In 2000, Randy Thornhill’s ‘The Natural History of Rape’ put forward the argument that rape is an adaptation, which drew strong criticism from evolutionary biologists and society at large. In 2003, a collection of essays by various scholars opposing this claim was also published.
Jang Dae-ik’s book addresses the issue of rape through the theme of “the power of natural selection,” presenting a simulated debate among experts from various fields. Proponents of the adaptation theory argue that rape is a behavior that has increased men’s reproductive success. They cite as evidence that rape can serve as a means of reproduction, particularly for males who have difficulty mating, and point to examples in some insect species where physical structures facilitating rape have evolved.
On the other hand, anti-adaptationists counter that the evidence is insufficient to draw such a conclusion. They argue that it is difficult to generalize rape as an adaptation solely for reproductive gain, pointing out that a high proportion of rape victims are children and that there are cases unrelated to reproduction, such as same-sex or incestuous rape.
A key issue in this debate is “from which perspective the evidence is interpreted.” Key questions remain: whether examples from insects or other animals can be directly applied to humans, and how rape occurring in situations of war or social disorder can be interpreted from an evolutionary perspective.
Historical and Contemporary Examples and Adaptationist Interpretations
The author supports the view that rape is the result of an evolutionary adaptation. Historically, rape appears to be a very ancient phenomenon, found in both myths and historical records.
Rape has occurred repeatedly in situations of collective violence, such as numerous wars, and has sometimes been interpreted as an act with a specific purpose rather than merely a spontaneous crime.
During wars, rape was sometimes used with the intent to break the enemy’s morale and influence the demographic composition of the population; in other cases, invaders sought to settle in the region through forced sexual relations with women in the occupied territories. These phenomena suggest the possibility that the act of rape was linked to reproduction and actually had an effect.
Modern examples include the systematic rape perpetrated by military forces during the occupation of East Timor in the late 20th century and the rape camps during the Bosnian War. In East Timor, there are reports that soldiers raped local women and settled in the region, and in Bosnia, it is known that there were instances where mass rape was used to target the reproduction of specific ethnic groups. These incidents demonstrate the possibility that rape actually contributed to reproduction.
It is also noteworthy that, historically, the vulnerable—slaves, people conquered during wartime, and prison inmates—have been the primary targets of rape, and that rape occurred frequently when social order collapsed, such as during wartime or disasters. In such contexts, since perpetrators often went unpunished or were even condoned by the state, it is highly likely that rape did not result in outcomes detrimental to reproduction.
Practical examples such as the right of the first night in medieval Europe illustrate situations where rape was culturally tolerated or structurally condoned. Even if punitive norms existed, if their enforcement was insufficient, men who committed rape would have gained reproductive opportunities from a natural selection perspective, allowing their traits to be maintained.
In modern society, rape is regulated by law and ethics, but it remains prevalent when order breaks down, such as during wartime or disasters. This recurrence suggests that the desire for and patterns of rape are inherent in human groups, and that social controls merely suppress them under normal circumstances.
It is difficult to rigorously prove whether rape actually increased reproductive rates. However, logically speaking, if a soldier had left without committing rape during a war, the reproductive opportunity in that instance would be zero. On the other hand, since the probability of pregnancy resulting from rape is greater than zero, it could confer a reproductive advantage in the absence of punishment or fatal consequences. Furthermore, even if the man who committed the rape already had a wife, he could gain additional reproductive opportunities, so this may have acted as a selective pressure.
In modern times, if rape acts to hinder reproduction, such behavior is likely to decrease over time; however, since adaptation changes slowly over long periods, it will not disappear in the short term. Furthermore, if chaotic situations such as war, disasters, and social collapse continue to recur in the future, there will still be room for the relative reproductive advantage of rape to come into play each time.
Finally, it is important to note that an explanation based on adaptation does not imply the ethical justification of the behavior. Just because a trait is an “adaptation” does not mean it is right. For example, the human eye has a blind spot, a defect that was inevitably formed along the course of evolution. While it is possible to understand the origins of rape through an evolutionary biological explanation, its consequences should not be morally justified.
Understanding the phenomenon of rape from an evolutionary perspective can help in solving the problem and developing response strategies. Rather than ignoring this and merely condemning the behavior, it would be more realistic and constructive to scientifically examine why such behavior occurs and to make efforts to curb its manifestation through social and legal institutions, education, and disaster response systems.
