Toward a biologically informed psychology of personality.

This article describes nine ways in which biological approaches can inform issues of central and long-standing concern to personality psychologists. These include: (a) developing an adequate description of human nature, (b) providing several solutions to the puzzle of within-species genetic variability, (c) identifying the most important ways in which individuals differ, (d) giving precision to the concepts of adaptation and adjustment, (e) identifying the origins of personality dispositions, (f) providing insight into personality development and the life course, (g) providing conceptual and evidential standards for invoking personality types as opposed to personality dimensions, (h) addressing the psychophysiology of personality, and (i) focusing attention on psychological mechanisms as evolved dispositional strategies.