Personality change over 40 years of adulthood: Hierarchical linear modeling analyses of two longitudinal samples

Abstract

Normative personality change over 40 years was shown in 2 longitudinal cohorts with hierarchical linear modeling of California Psychological Inventory data obtained at multiple times between ages 21–75. Although themes of change and the paucity of differences attributable to gender and cohort largely supported findings of multiethnic cross-sectional samples, the authors also found much quadratic change and much individual variability. The form of quadratic change supported predictions about the influence of period of life and social climate as factors in change over the adult years: Scores on Dominance and Independence peaked in the middle age of both cohorts, and scores on Responsibility were lowest during peak years of the culture of individualism. The idea that personality change is most pronounced before age 30 and then reaches a plateau received no support. Whether and how personality is related to age over the adult years has been a controversial topic over the last 2 decades. Diverse views have been asserted and defended empirically. For example, Costa and McCrae (1980) made the case that personality does not change, Helson and Stewart (1994) claimed that virtually all aspects of personality show change along with consistency, and Lewis (1999) stated that personality is primarily influenced by current context and constructed personal narrative. In the midst of this diversity, an important development is a convergence of findings in several recent personality inventory studies using cross-sectional multinational samples. Some of these studies (McCrae et al., 1999, 2000) have used the Revised NE