Evolutionary personality psychology suggests that human personality variation is a meaningful and relevant source of human diversity, and that different combinations of heritable personality traits biologically prepare individuals to exploit the different social niches they inhabit. Human personality variation relates to numerous important life outcomes, including life history traits such as sexuality, sociality, fertility, morbidity, and mortality. The effects of personality variation upon these fitness-relevant demographic parameters renders such variation subject to both natural and sexual selection. Furthermore, the adaptive value of any given personality trait is relative to that circumscribed portion of the environment which the individual habitually inhabits (i.e., the individual's physical and social niche), and in which the individual is functioning. Any given personality trait can be evaluated as an adaptive function or harmful dysfunction by determining its match to the particular social niche a person occupies within a particular social environment.
This entry explains the complex mix of genetic and environmental influences on human personality variation by applying a combination of the predictions of Brunswikian evolutionary developmental theory and developmental plasticity theory. This entry also considers the significance of personality disorders from the perspectives of the mismatch hypothesis and the harmful dysfunction hypothesis.
Encyclopedia of Counseling: Personal and Emotional Counseling
Figueredo, A. J., Vasquez, G., & Sefcek, J. A. (2008). Personality theories, evolutionary. In F. T. L. Leong (Ed.) Encyclopedia of counseling (Vol. 2, pp. 749-752). Thousand Oaks, CA: Sage.