Evolutionary psychology - conceptual foundations

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Evolutionary psychology: Conceptual foundations
John Tooby and Leda Cosmides Center for Evolutionary Psychology, University of California, Santa Barbara

Handbook of Evolutionary Psychology David M. Buss, Editor. Revised Draft: January 16, 2005

Note. We dedicate this chapter to Irven DeVore, Professor Emeritus, Department of Anthropology, Harvard University, on the occasion of his 70thbirthday.

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2 Intellectual origins of evolutionary psychology The theory of evolution by natural selection has implications for understanding the design of the human mind, and Darwin himself was the first to see this. During the 20th century, many thinkers tried to work out exactly how Darwin’s fundamental insights could be used as a foundation on which to build a more systematic approachto psychology. This resulted in many valuable approaches: the instinct psychology of William James and William McDougall; human ethology, which applied the framework for studying how animals behave in their natural environment, developed by Karl von Frisch, Konrad Lorenz and Niko Tinbergen; Skinnerian psychology, which looked for phylogenetic continuities in the laws of learning that would applyacross species; and sociobiology, which tried to understand patterns of social behavior— differences as well as universals—in humans and other primates in light of a set of exciting and rigorous new theories then emerging about how natural selection works. Our own early training included this last approach, which was flourescing in Irven DeVore’s living room where Harvard’s Simian Seminar was heldduring the 1970s and early 1980s. DeVore was a pioneering thinker, deeply interested in human origins, who instigated and then championed the study of primate social behavior under natural conditions and the study of modern hunter-gatherers. Eschewing the “lone anthropologist” model, in which a single individual spends time learning “the” culture of a people, DeVore and his colleague, Richard Lee,innovated a team-based approach like that found in other sciences. Their Kalahari San project brought scientists and scholars from a vast array of disciplines—anthropologists, physicians, linguists, folklorists, psychologists, ethologists, archeologists—in an attempt to document as completely as possible the lifeways of the !Kung San people in Botswana’s Kalahari desert, before hunting andgathering as a way of life vanished from the planet. DeVore did not do this because he thought the San’s way of life was the single prototype for our huntergatherer ancestors or even the best example of the biotic environment in which humans evolved—he was well aware that the San had been pushed into one of the harshest and most unforgiving biotic environments on earth by the encroachment ofagricultural populations. His goal in studying the San was to provide a detailed database which, when trianguated with other similarly detailed databases drawn from other hunter-gatherer groups, would allow new and powerful inferences to be made about human origins and behavior. Behavioral ecologists would be able to test optimal foraging models by matching foraging patterns to ecological conditions.Archaeologists could better interpret patterns found at ancestral sites by seeing patterns of campfires, animal remains, tool-making debris, and midden heaps produced by the social life of living hunter-gatherers. Physicians could gain insight into “diseases of civilization” by comparing diets and conditions in industrialized countries to the diets and stressors produced by a way of life that moreclosely resembles the conditions in which our species evolved. Developmental psychologists could understand more about the mother-infant bond and human attachment when babies are nursed and women are gathering food. Anthropologists could learn what social conditions foster risk-pooling and food sharing, what kinds of knowledge huntergatherers have about animal behavior and plant life, how they use...