In this blog post, we explore whether the act of rape is an evolutionary adaptation or part of a gene propagation strategy.

Rape and Evolution

Some organisms developed gills to adapt to aquatic environments, while certain plants evolved nectar glands to attract insects. In this way, all organisms existing on Earth today have continuously evolved to keep pace with an ever-changing environment. Over the long course of evolution, animals have optimized their own strategies for survival and reproduction to ensure their genes are passed on more frequently and effectively. In other words, organisms can be seen not as individuals existing for themselves, but as tools for the survival and proliferation of the genes that compose them.
From this evolutionary perspective, can ‘male rape’ truly be considered an evolutionary adaptation for survival and reproduction?
The book Darwin’s Table uses fictional characters to explore various topics related to evolutionary theory through discussion formats, guiding readers toward deep reflection. Characters in the book, such as Cosmides, argue that “male rape behavior could also be a product of evolutionary adaptation.” They adopt an attitude of seeking to scientifically understand why rape occurs and what patterns it exhibits, before considering it a matter of ethical right or wrong. They state that the foundation of this understanding lies precisely in the concept of ‘adaptation’.
I wish to examine this claim from two perspectives: “Does the act of rape actually provide favorable conditions for the reproduction of male genes?” and “Did the act of rape evolve due to the pressures of natural selection?”

What is evolutionary ‘adaptation’?

Before delving into the main discussion, it is necessary to clearly understand the concept of ‘adaptation’ as defined in evolutionary biology. The Encyclopedia of Life Sciences defines adaptation as follows:

“The state in which various traits of an organism, such as its form, physiology, ecology, and behavior, are suited to living in its environment, or traits that contribute to the survival and reproductive success of an individual organism.”

However, not every trait that appears advantageous for survival and reproduction can immediately be called an ‘evolutionary adaptation’. Evolutionary psychologist George Williams issues this warning regarding the concept of adaptation:

“Adaptation can only be produced by natural selection, and therefore it is a special and demanding concept that should not be used carelessly. Just because a phenomenon appears designed does not mean it can immediately be called a function or an adaptation.”

In other words, not every behavior that offers even a slight advantage for survival and reproduction can be classified as an evolutionary adaptation; it must also repeatedly emerge ‘as if designed’ through natural selection. So, by this standard, can male rape truly be considered an evolutionary adaptation?

Does rape contribute to reproductive success?

Richard Dawkins mentions the following in The Selfish Gene:

“Although each parent contributes 50% of the genetic material to their offspring, both parents seek to maximize the benefit from their investment. Thus, they cooperate while pursuing a selfish strategy. If one parent could invest fewer resources in their offspring and then escape, they would be able to leave behind more offspring, making this advantageous from the gene’s perspective.”

This perspective can also be applied to rape. Generally, rape can be a way for men to gain reproductive opportunities without emotional or economic responsibility, and indeed, in many cases, perpetrators do not take responsibility for children born from rape. If gene transmission is possible with such low investment costs, this could be advantageous from an evolutionary perspective.
Moreover, rape allows males to mate with females possessing specific genetic traits by choice, potentially making it more advantageous for the qualitative propagation of genes than typical mating involving mutual selection.
In other words, rape provides conditions favorable for reproduction, potentially meeting the first criterion for adaptation: ‘contributing to survival and reproduction’.

Is rape a strategy induced by natural selection pressure?

The second condition is ‘whether the behavior evolved under selective pressure from natural selection.’ In other words, we must examine whether the behavior of rape possessed survival or reproductive advantages sufficient to prevent its elimination by natural selection.
In this regard, rape can function as an alternative reproductive strategy for males excluded from mating opportunities. For example, research on walruses shows that 88% of observed matings are concentrated among the top 4% of males. This structure means only a few males monopolize the majority of reproductive opportunities, while the rest effectively have no chance to reproduce.
Human societies have also historically shown a tendency for reproductive opportunities to be concentrated among a few males, leaving males not chosen by females with an extremely low chance of passing on their genes. In such situations, rape could be a strategy chosen by males unable to obtain reproductive opportunities as a last resort to leave their genes behind. This implies it is a behavior that can be maintained at a certain rate due to natural selection pressure.

Considerations on Counterarguments

The position that rape is not adaptive presents two main grounds.
First, the survival rate of children born from rape is low.
Second, rape negatively impacts the perpetrator’s survival potential due to social punishment or stigma.
However, these two counterarguments lose persuasiveness when viewed on an evolutionary timescale. Regarding the first counterargument, even if survival rates are low, as long as they are not zero, the mere acquisition of the probability to have offspring can constitute an advantageous strategy in evolutionary selection. Having no reproductive opportunity at all is fundamentally different from attempting reproduction, even with a low probability. The difference between zero and one is enormous from an evolutionary perspective.
The second counterargument, social punishment, also has limited impact on the evolutionary timescale. Social sanctions and penal systems emerged relatively recently in human evolutionary history. For most of the millions of years humans evolved, such legal and moral systems did not exist. During that period, it cannot be ruled out that rape provided tangible benefits for survival or reproduction. Whether an action is an evolutionary adaptation must be evaluated based on the long-term process of natural selection, separate from current societal ethical judgments or the presence of punishment.

Conclusion

Based on the analysis so far, male rape behavior can be seen as satisfying both conditions for evolutionary adaptation: (1) it aided survival and reproduction, and (2) it was induced by natural selection pressures.
First, rape provides males who lack mating opportunities with the possibility of fathering offspring, offering favorable conditions for reproduction by enabling gene transmission with low parental investment.
Second, rape could function as a strategy chosen by males excluded from reproduction to transmit their genes, suggesting it may have arisen under pressure from natural selection.
Therefore, from this scientific and evolutionary perspective, the argument that rape could be the result of an evolutionary adaptation holds a certain degree of persuasiveness. Clearly, this issue transcends simple ethical value judgments and remains a subject that should continue to be discussed at the complex intersection of human nature and evolutionary psychology.