Adapting Minds and Evolutionary Psychology∗

The human brain is the result of a long evolutionary trajectory. Using this fact to understand the human brain’s particular capacities and limitations, evolutionary psychology has provided many key insights into human behavior. First, since the human brain is extremely costly to nurture and maintain, its general contribution to human fitness must be high, and hence the brain must be an adaptation to the particular conditions under which our species evolved. Therefore, understanding these conditions may shed strong light on human psychology. Second, the human brain’s information processing capacities are likely to be closely associated with the particular adaptive needs of our species, rather than being a simple, general purpose information processor. Thus, rather than being infinitely malleable, humans are predisposed to behave in certain ways in the sense that under a very broad range of environmental conditions some behaviors will be virtually universally exhibited and others will be extremely rare, while behaviors to which we are not predisposed will be exhibited either not at all, or only in a very restricted set of environmental circumstances. Third, since biological fitness is a scalar variable, and since the brain’s characteristics are selected for maximizing fitness, human decision making will, at least approximately, exhibit choice transitivity, which decision theory tells us implies that agents can be modeled as maximizing a preference function subject to constraints. This is called the rational actor model in economics and decision theory, but a more apt term is the beliefs, preferences, and constraints model (BPC). In short, evolutionary psychology suggests that a consideration of our evolutionary history is extremely powerful in generating plausible hypotheses concerning human psychology that can be tested using the standard tools of experimental research. More generally, and following a famous dictum of the great Russian geneticist Theodore Dobzhansky, the human mind makes sense only in the light of evolution. The central commitment of evolutionary psychology is that the human mind is an adaptation that can be most effectively modeled by a careful study of the ∗To appear in the Journal of Bioeconomics. The author is External Faculty, Santa Fe Institute, and Professor of Economics, Central European University. Email: [email protected]. Web site: http://www-unix.oit.umass.edu/g̃intis.