Behavioral genetics and evolutionary psychology: Unified perspective on personality research

Human Biology, Apr 1998 by Segal, Nancy L, MacDonald, Kevin B

A hierarchical model is also applicable to behavioral approach and nurturance/love. Buss (1991) emphasized the importance of considering evolutionary goals in personality psychology, such as acquiring mates, negotiating dominance hierarchies, and forming reciprocal alliances. The goals of affiliation-intimacy and power have been central to several important recent approaches to personality [e.g., McAdams (1985)]. Variation in these systems appears to influence the extent to which people are motivated to seek out discrete types of stimulation that satisfy evolutionarily derived reward systems. Thus an individual high on nurturance/love is motivated to seek out the rewards of intimate long-term relationships with family members and close friends; such a person values these relationships highly and actively maintains such relationships. Individuals high on dominance are highly motivated to control others, whereas individuals high on sensation seeking are attracted to short-term sexual relationships (presumably motivated, at least in part, by the pleasure of sexual intercourse), risk taking, and physically dangerous situations.

The result is a hierarchical model in which the highest levels often involve affective goals subsumed by the evolved systems underlying what MacDonald (1991, 1995) termed evolved motive dispositions. Such a perspective provides a robust role for general-purpose cognitive processes (schemas, tasks, and strategies) used in attempting to achieve these goals and in evaluating situations relevant to achieving affective goals. Secondarily reinforcing rewards, such as money, would then be conceptualized as lower-level goals that can be used to facilitate the attainment of evolved motive dispositions at the highest level.

Behavioral Genetics in Evolutionary Perspective: Focus on Individual Differences

Behavioral genetics aims to identify genetic and environmental influences underlying individual differences in behavior. Ever since formal definition of the field by Fuller and Thompson (1960) in their comprehensive volume, Behavior Genetics, research activity has focused on demonstrating genetic influence across a wide range of human behaviors. Genetic influence has proven to be pervasive: In addition to explaining variation in intellectual abilities and personality traits, recent analyses have demonstrated genetic influence on social attitudes (Posner et al. 1996), religious beliefs (Waller et al. 1990), job satisfaction (Arvey et al. 1989), and divorce (McGue and Lykken 1992). One of the most significant recent developments in the field has been characterization of the environment. Beginning with Plomin and Daniels's (1987) landmark review, there has been growing evidence that the critical environmental factors relevant to the development of many intellectual and personality traits are those that are unique to individuals (idiosyncratic or nonshared environmental factors) rather than those that are shared with family members (common or shared environmental factors).