Scientists and philosophers submit personal reflections on the significance and influence of Darwin’s theory and of current views of evolution within contemporary psychology.
In commemoration of the 200th anniversary of Charles Darwin’s birth and the 150th anniversary of the publication of his seminal work On the Origin of Species, this edition of Psychological Science Agenda includes a special section on evolutionary theory and psychology. Scientists and philosophers were invited to submit personal reflections on the significance and influence of Darwin’s theory and of current views of evolution within contemporary psychology. PSA thanks the authors for their provocative contributions.
By David M. Buss
By Daniel Kruger
By Robert Kurzban
By Debra Lieberman and Martie Haselton
By Edouard Machery
By Gary Marcus
By Daniel J. Povinelli, Derek C. Penn, and Keith J. Holyoak
By Wendy Wood and Alice H. Eagly
Darwin’s Influence on Modern Psychological Science
By David M. Buss
David M. Buss is Professor of Psychology at the University of Texas at Austin.
At the end of his classic treatise in 1859, On the Origin of Species, Darwin envisioned that in the distant future, the field of psychology would be based on a new foundation—that of evolutionary theory. A century and a half later, it’s clear that his vision proved prescient (Buss, 2009).
Evolutionary psychology is not a distinct branch of psychology, but rather a theoretical lens that is currently informing all branches of psychology. It is based on a series of logically consistent and well-confirmed premises: (1) that evolutionary processes have sculpted not merely the body, but also the brain, the psychological mechanisms it houses, and the behavior it produces; (2) many of those mechanisms are best conceptualized as psychological adaptations designed to solve problems that historically contributed to survival and reproduction, broadly conceived; (3) psychological adaptations, along with byproducts of those adaptations, are activated in modern environments that differ in some important ways from ancestral environments; (4) critically, the notion that psychological mechanisms have adaptive functions is a necessary, not an optional, ingredient for a comprehensive psychological science.
Darwin provided two key theories that guide much of modern psychological research—natural selection and sexual selection. These theories have great heuristic value, guiding psychologists to classes of adaptive problems linked with survival (e.g., threats from other species such as snakes and spiders; threats from other humans) and reproduction (e.g., mate selection, sexual rivalry, adaptations to ovulation). Advances in modern evolutionary theory heralded by inclusive fitness theory and the “gene’s-eye” perspective guide researchers to phenomena Darwin could not have envisioned, such as inherent and predictable forms of within-family conflict and sexual conflict between males and females.
Over the past decade, evolutionary psychology has increasingly informed each sub-discipline within psychology. In perception and sensation, it has led to the discovery of phenomena such as the auditory looming bias and the visual descent illusion. In cognitive psychology, based on a fusion of signal detection theory and the asymmetric evolutionary costs of cognitive errors, it has led to error management theory and the discovery of functional cognitive biases that are, strange as it may seem, “designed” to err in adaptive ways. Evolutionary social psychology has produced a wealth of discoveries, ranging from adaptations for altruism to the dark sides of social conflict. Evolutionary developmental psychology has explored the ways in which critical ontogentic events, such as father absence versus father presence, influence the subsequent development of sexual strategies.
Evolutionary clinical psychology provides a non-arbitrary definition of psychological disorder-when an evolved mechanism fails to function as it was designed to function. It also sheds light on common afflictions such as depression, anxiety disorders, eating disorders, and sexual disorders. And it provides a framework for examining how mismatches between ancestral and modern environments can create psychological disorders. Personality psychology, historically refractory to evolutionary analysis, is finally beginning to discover adaptive individual differences.
Hybrid disciplines too make use of the tools of evolutionary psychology. Cognitive and social neuroscientists, for example, use modern technologies such as fMRI to test hypotheses about social exclusion adaptations, emotions such as sexual jealousy, and kin recognition mechanisms.
More generally, evolutionary psychology breaks down the barriers between the traditional sub-disciplines of psychology. A proper description of psychological adaptations must include identifying perceptual input, cognitive processing, and developmental emergence. Many mechanisms evolved to solve social adaptive problems, such as when social anxiety functions to motivate behavior that prevents an individual from losing status within a group. And all adaptations can malfunction, as when social anxiety becomes paralyzing rather than functional, making clinical psychology relevant. The key point is that organizing psychology around adaptive problems and evolved psychological solutions, rather than around the somewhat arbitrary sub-fields such as cognitive, social, and developmental, dissolves historically restrictive branch boundaries. Evolutionary psychology provides a metatheory for psychological science that unites these fields, and justifies why the seemingly disparate branches of psychology truly belong within the covers of introductory psychology books and within the same departments of psychology.
Buss, D. M. (2009). The great struggles of life: Darwin and the emergence of evolutionary psychology. American Psychologist, 64, 140-148.
Evolutionary Psychology and the Evolution of Psychology
By Daniel J. Kruger
Daniel Kruger is Research Assistant Professor at the Prevention Research Center of Michigan, in the School of Public Health at the University of Michigan.
The framework of evolutionary theory will be increasingly adopted as the foundation for a cumulative understanding of psychological science. As the unifying theory of the life sciences, evolution by natural and sexual selection offers an unparalleled ability to integrate currently disparate research areas (Wilson, 1998), creating a powerful framework for understanding the complex patterns of causality in psychological and behavioral phenomena. The evolutionary perspective will grow from its perceived status as a special interest area into an organizing principle that pervades every corner of every field, as well as serve as a bridge across levels of analysis.
The incorporation of evolutionary theory into psychology has waxed and waned in the 150 years since Darwin (1859) predicted that the field would be based on a new foundation. There are many notable examples of psychological theories with evolutionary bases, such as Bowlby’s (1969) model of attachment, yet these are often isolated examples. In the last three decades, the evolutionary perspective has been reinvigorated with considerable theoretical advances and a continually growing array of empirical studies.