Darwinian psychology, old and new.

Many senior American and British psychologists between c1890 and c1925 were engaged in an attempt to settle on a unified definition of the term "instinct" as a psychological construct. Whilst this enterprise failed, some of its basic concepts underpin today's project of evolutionary psychology. This claim is substantiated by an analysis of the similarities between William McDougall's "Social Psychology" (1908), in which he articulated his theory of instincts, and John Tooby's and Leda Cosmides' "The Psychological Foundations of Culture" (1992). It is argued that Tooby's and Cosmides' approach faces similar problems as were faced by McDougall's theory of instincts.