19th Century
After his seminal work in developing theories of natural selection, Charles Darwin devoted much of his final years to the study of animal emotions and psychology. He wrote two books;The Descent of Man, and Selection in Relation to Sex in 1871 and The Expression of the Emotions in Man and Animals in 1872 that dealt with topics related to evolutionary psychology. He introduced the concepts of sexual selection to explain the presence of animal structures that seemed unrelated to survival, such as the peacock’s tail. He also introduced theories concerning group selection and kin selection to explain altruism. Darwin pondered why humans and animals were often generous to their group members. Darwin felt that acts of generosity decreased the fitness of generous individuals. This fact contradicted natural selection which favored the fittest individual. Darwin concluded that while generosity decreased the fitness of individuals, generosity would increase the fitness of a group. In this case, altruism arose due to competition between groups. The following quote, from Darwin’s Origin of Species, is often interpreted by evolutionary psychologists as indication of his foreshadowing the emergence of the field:
In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation.
— Charles Darwin, The Origin of Species, 1859, p. 449.
Darwin’s theory inspired William James’s functionalist approach to psychology. At the core of his theory was a system of “instincts.” James wrote that humans had many instincts, even more than other animals. These instincts, he said, could be overridden by experience and by each other, as many of the instincts were actually in conflict with each other.
According to Noam Chomsky, perhaps Anarchist thinker Peter Kropotkin could be credited as having founded evolutionary psychology, when in his 1902 book Mutual Aid: A Factor of Evolution he argued that the human instinct for cooperation and mutual aid could be seen as stemming from evolutionary adaption.
Post World War II
While Darwin’s theories on natural selection gained acceptance in the early part of the 20th century, his theories on evolutionary psychology were largely ignored. Only after the second world war, in the 1950s, did interest increase in the systematic study of animal behavior. It was during this period that the modern field of ethology emerged. Konrad Lorenz and Nikolaas Tinbergen were pioneers in developing the theoretical framework for ethology for which they would receive a Nobel prize in 1973.
Desmond Morris’s book The Naked Ape attempted to frame human behavior in the context of evolution, but his explanations failed to convince academics because they were based on a teleological (goal-oriented) understanding of evolution. For example, he said that the pair bond evolved so that men who were out hunting could trust that their mates back home were not having sex with other men.
Sociobiology
In 1975, E O Wilson built upon the works of Lorenz and Tinbergen by combining studies of animal behavior, social behavior and evolutionary theory in his book Sociobiology:The New Synthesis. Wilson included a chapter on human behavior. Wilson’s application of evolutionary analysis to human behavior caused bitter divisions between biologists.
With the publication of Sociobiology, evolutionary thinking for the first time had an identifiable presence in the field of psychology. E O Wilson argues that the field of evolutionary psychology is essentially the same as sociobiology. According to Wilson, the heated controversies surrounding Sociobiology:The New Synthesis, significantly stigmatized the term “sociobiology”.
Origin of Evolutionary Psychology
The term evolutionary psychology was probably coined by American biologist Michael Ghiselin in a 1973 article published in the journal Science. Jerome Barkow, Leda Cosmides and John Tooby popularized the term “evolutionary psychology” in their highly influential 1992 book The Adapted Mind: Evolutionary Psychology and The Generation of Culture.
Evolutionary psychologists emphasized that organisms are “adaptation executors” rather than “fitness maximizers.” In other words, organisms use behaviors that were adpative in the past rather than those that maximize fitness in the present. This distinction helps explain maladaptive behaviors, which are “fitness lags” resulting from novel environments. In addition, rather than focus primarily on overt behavior, EP attempts to identify underlying psychological adaptations (including emotional, motivational and cognitive mechanisms), and how these mechanisms interact with the developmental and current environmental influences to produce behavior.
Before 1990, introductory psychology textbooks scarcely mentioned Darwin. In the 1990s, evolutionary psychology was treated as a fringe theory, and evolutionary psychologists depicted themselves as an embattled minority. Coverage in psychology textbooks was largely hostile. According to evolutionary psychologists, current coverage in psychology textbooks is usually neutral or balanced.
The presence that evolutionary theory holds in psychology has been steadily increasing. According to its proponents, evolutionary psychology now occupies a central place in psychological science.