Psychological adaptation

A psychological adaptation, also called an evolved psychological mechanism or EPM, is an aspect of a human or other animal's psychology that serves a specific purpose, and was created and selected by evolutionary pressures. Evolutionary psychology proposes that the human psychology mostly comprises psychological adaptations, in opposition to blank slate models of human psychology such as the Standard Social Sciences Model, popular throughout most of the twentieth century.

Evolutionary psychologist, David Buss, lays out six properties of evolved psychological mechanisms (EPM's): a specific problem of survival or reproduction recurrently over evolutionary history.
 * (1) An EPM exists in the form that it does because it solved
 * (2) An EPM is designed to take in only a narrow slice of information
 * (3) The input of an EPM tells an organism the particular adaptive problem it is facing
 * (4) The input of an EPM is transformed through decision rules into output
 * (5) The output of an EPM can be physiological activity, information to other psychological mechanisms, or manifest behaviors
 * (6) The output of an EPM is directed toward the solution to a specific adaptive problem

Further important properties include the following:
 * EPM's provide nonarbitrary criteria, (i.e. adaptive function) for "carving the mind at its joints," (i.e. evolved structure).
 * EPM's tend to aid in solving specific adaptive problems, (e.g. food selection, mate selection, intrasexual competition, etc.)
 * EPM's are believed to be numerous, which contributes to human behavioral flexibility. An analogy would be like a carpenter who, instead of having one tool that does everything, has many tools, each with a specific function for a specific task, (e.g. a hammer for pounding nails, a saw for cutting wood, etc.)
 * Some EPM's are domain-specific, (i.e. evolved to solve specific, recurrent adaptive problems), while others are domain-general, (i.e. evolved to aid the individual in dealing with novelty in the environment).

The least controversial EPMs are those commonly known as instincts, including interpreting stereoscopic vision, suckling a mother's breast, etc.