This blog post examines the evidence supporting the claim that evolutionary psychology scientifically explains human behavior, along with critical issues surrounding this claim, and thoroughly reviews the validity of this theory.
Biologist Charles Darwin, at the conclusion of his seminal work On the Origin of Species (1869), which opened new horizons for evolutionary theory, left this prediction: “In the distant future, the study of human psychology will be conducted on a new foundation.” Darwin’s foresight began to gain a realistic foundation in 1975 when biologist Edward O. Wilson published Sociobiology: The New Synthesis, which explained human behavior and psychology from an evolutionary perspective. Marking this book as a turning point, evolutionary psychology began to develop in earnest within mainstream academia through the work of scholars such as David Buss and Steven Pinker.
Evolutionary psychology is a discipline combining cognitivism and evolutionary theory, focusing on the origins of the psychological mechanisms that drive specific human behaviors. The core claim of evolutionary psychologists is that throughout the long evolutionary process, humanity faced diverse adaptive challenges, and only individuals with minds designed to solve these problems achieved evolutionary success. They view genes, formed through cumulative natural selection, as influencing human psychology. They actively support and utilize the perspective presented in Richard Dawkins’ The Selfish Gene (1976)—which explains the behavior of males and females in the animal world from an evolutionary standpoint and regards an individual’s body as a machine for gene propagation. Evolutionary psychology extends this evolutionary perspective into psychological analysis, arguing that men and women have developed inherently different adaptive mechanisms based on their respective environments. While evolutionary psychology offers a fresh approach by framing natural selection as the solution to humanity’s adaptive challenges, it also necessitates careful consideration of whether explaining behavior through fundamental differences in male and female nature is scientifically credible.
The first problem with evolutionary psychology is its tendency to overly reduce all human behavior to an evolutionary perspective—that is, to explain humans as beings who act solely for the sake of evolution and survival. This perspective contradicts modern views on romantic relationships. A prime example is the theory of sexual selection. According to its typical explanation, “Men court, women choose.” Women, needing only to choose among men showing interest, supposedly have no need to develop attractive traits to appeal to the opposite sex, as men do. The Selfish Gene attributes this cause to the biological difference that while men’s sperm is effectively infinitely supplied, women’s eggs are numerically limited. The explanation is that because women must invest more time and energy than men in sexual intercourse and childbirth, they inevitably become more cautious in the mate selection process. Ultimately, evolutionary psychology, based on Darwin’s theory of sexual selection, has culminated in a theory that reproduces the archetype of “the actively courting male and the demure female.”
However, this narrative lacks sufficient scientific sophistication. Human sexual relations are not solely motivated by reproduction through sperm transfer, as in animal mating. In modern human society, sex is also a crucial means of forming and maintaining romantic relationships between partners. This raises another problem: instances deviating from the norms of sexual selection theory are consistently found, both historically and currently, among humans and animals alike. For instance, male sexual refusal, female sexual promiscuity, and same-sex sexual behavior are examples that do not conform to the normative form proposed by sexual selection theory. Nevertheless, current sexual selection theory fails to explain these numerous exceptions and counterexamples. It dismisses them as simply irrational or abnormal phenomena, dominating popular science books related to evolutionary theory.
Can the evolutionary imperative to produce as many offspring as possible truly explain every aspect of human behavior? Evolutionary psychology fails to align with modern perspectives by overly reducing deep relationships between the sexes to mere reproduction. Male Parental Investment (MPI) is cited as a counterexample to this. From an evolutionary psychology perspective, men are expected to focus primarily on the ‘number’ of offspring, remaining relatively indifferent to the quality of those offspring—that is, how they are raised. However, strong paternal affection exists in actual human males, a fact clearly confirmed by modern neuroscience. Moreover, unlike animals, humans accumulate complex social environments and cultural experiences, developing a more intricate and deeply structured paternal affection based on these. Viewed in this context, evolutionary psychology’s attempt to distinguish between genders in the loving hearts of parents fails to fully explain the high level of MPI observed in human society. Reducing human behavior, which can be more convincingly explained through cultural influences, to genetic or psychological mechanisms solely for unconditional reproduction is an overly extreme and biased interpretation.
The second problem with evolutionary psychology is that it reinforces a binary mindset that seeks to explain humanity solely through the polarized distinction of male and female. Evolutionary psychology argues that males and females have developed inherently different adaptive mechanisms within their respective environments. A representative example is the narrative that males, accustomed to hunting, are aggressive, goal-oriented, and combative, while females, responsible for survival activities within the community, value relational bonds and close communication. It is also argued that males pursue one-night stands to obtain more offspring from multiple females, whereas females, needing to raise their children, prefer males who are economically secure and family-oriented. These explanations overlook crucial contexts regarding how men and women are socialized into differentiated gender roles through cultural interactions. They are problematic because they reduce differences between men and women to immutable laws of human nature—namely, the action of selfish genes solely focused on reproduction. This perspective carries the risk of legitimizing widespread gender stereotypes in human society as scientific fact.
In this regard, gender studies scholar Mari Ruti strongly criticizes evolutionary psychology, arguing that it legitimizes overt gender stereotypes deeply embedded in culture and constitutes pseudoscience based on sexism. Deriving the conclusion that men inherently possess psychological mechanisms suited for infidelity and women for child-rearing based on differences in male and female germ cells lacks systematic logic. It ignores the possibility of third variables and hastily infers causation from mere correlation. As mentioned earlier, such explanations also contradict modern thinking on gender roles. Furthermore, this logical leap and rigid assumptions about gender roles are amplified as evolutionary psychology spreads through popular science books. For example, John Gray’s self-help book Men Are from Mars, Women Are from Venus (1992) presents the belief that conflicts between men and women arise because they have lived in fundamentally different psychological and emotional worlds since the beginning. This overlooks the fact that romance is an encounter between individuals, and that various factors—such as each person having grown up in different environments, ontological conflicts, unconscious motivations, and vulnerabilities revealed in intimate relationships—can contribute to conflict. Such simplified beliefs spread rapidly through self-help books, magazine articles, popular culture sites, and talk shows, serving to justify and reinforce gender stereotypes.
The fundamental reason evolutionary psychology is controversial lies in its status as a discipline where the boundary between fact and value is ambiguous. It is an undeniable fact that male and female gametes exhibit clear differences in terms of quantity and production rate. However, attempts to hastily define the inherent nature of men and women based on this fact involve a logical leap. Errors occur when conclusions are drawn based on average tendencies and generalized, especially when the population is unclear and various third variables are not adequately controlled. Marie Luti points out in her book, “When we reduce others to walking standardized models, we suppress their most vibrant and interesting aspects.” Evolutionary psychology does not fully acknowledge the possibility that men and women can share common interests and, as a result, may prefer partners who share their values, goals, and fundamental outlook on life. This is because, in evolutionary psychology, love, intimacy, and emotional courtship behaviors are reduced to secondary phenomena of economic calculations centered on reproduction. The narrative that heterosexual men focus solely on spreading their genes as widely as possible, and that heterosexual women’s lives are reduced to their ovarian age, limits the goal of human existence to fulfilling reproductive roles rather than achieving personal ideals.
Evolutionary psychologists claim their research represents a convergent exploration of human nature, integrating sociobiology, anthropology, cognitive science, and psychology. However, for evolutionary psychology to establish a clear scientific framework, rigorous scrutiny of the entire process by which its theories are produced, along with social oversight, is absolutely essential. This is a necessary condition to ensure that evolutionary psychology develops as a powerful attempt to explain human behavior, while preventing its explanations from reinforcing gender role stereotypes or biased value judgments.
