Is a non-evolutionary psychology possible?
The last thirty years has seen the emergence of a self-styled ‘evolutionary’ paradigm within psychology (henceforth, EP). EP is often presented and critiqued as a distinctive, contentious paradigm, to be contrasted with other accounts of human psychology. However, little attention has been paid to the sense in which those other accounts are not evolutionary, or at least evolutionalizable. We distinguish between a commitment to evolution, and a more specific commitment to adaptationism. We argue that all formulable accounts of human psychology are evolutionary in a real sense: non-evolutionary psychology is impossible. Not all psychologies are explicitly adaptationist, but those that are not still draw on informal notions of organismal function, and thus implicitly require at least a weak version of adaptationism. We argue that the really distinctive and contentious feature of EP is not its commitment to evolution, or even adaptationism. It is the commitment to domain-specificity and the associated multiplicity of innately specialized psychological mechanisms. This commitment entails a narrow parsing of what an adaptive problem is, and has the consequence that the science of psychology ends up consisting of many narrow proximal explanations, rather than a few broad ones. We illustrate this thesis by examining a range of paradigms that can be seen as competitors to canonical EP: social role theory; cultural evolutionary psychology and dual inheritance theory; Bayesian cognitive science; and Giddens’ social theory. Narrow versus broad functional specialization emerges as the central locus of difference between the different psychologies we review.