The study of the way in which a variety of higher mental functions may be adaptations, formed in response to selection pressures on human populations through evolutionary time. Candidates for such theorizing include maternal and paternal motivations, capacities for love and friendship, the development of language as a signalling system, cooperative and aggressive tendencies, our emotional repertoires, our moral reactions, including the disposition to detect and punish those who cheat on agreements or who free-ride on the work of others, our cognitive structures, and many others. Evolutionary psychology goes hand-in-hand with neurophysiological evidence about the underlying circuitry in the brain which subserves the psychological mechanisms it claims to identify. The approach was foreshadowed by Darwin himself, and William James, as well as the sociobiology of E. O. Wilson. See just so story.

http://www.psych.ucsb.edu/research/cep/primer.html Two pioneers of evolutionary psychology explain its basic principles

http://www.kli.ac.at/theorylab/Areas/ETSB.html A list of resources on evolutionary psychology and related fields