Rank-order consistency of personality traits increases from childhood to age 30. After that, different summaries of the literature predict a plateau at age 30, or at age 50, or a curvilinear peak in consistency at age 50. These predictions were evaluated at group and individual levels using longitudinal data from the Guilford-Zimmerman Temperament Survey and the Revised NEO Personality Inventory over periods of up to 42 years. Consistency declined toward a non-zero asymptote with increasing time-interval. Although some scales showed increasing stability after age 30, the rank-order consistencies of the major dimensions and most facets of the Five-Factor Model were unrelated to age. Ipsative stability, assessed with the California Adult Q-Set, was also unrelated to age. These data strengthen claims of predominant personality stability after age 30.
KeywordsFive-Factor Model; personality development; long-term stability; individual differences; life-span; older adults Since data from longitudinal studies appeared in the 1970s (e.g., Block, 1977), it has been clear that individual differences in personality traits are stable over long periods of time. Helson and Wink (1992) reported typical results in a sample of 101 women initially aged 43 and retested after 9 years: The median retest correlation for scales from the California Psychological Inventory (CPI; Gough, 1987) was .73. There is also considerable evidence that personality traits are more stable in adults than in adolescents. For example, Finn (1986) showed that the median 30-year retest correlation for factors from the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) was .35 for respondents initially aged 17 to 25, and .56 for respondents initially aged 43-53.However, there is disagreement about the degree of rank-order consistency in different portions of adulthood. Based on their own research and review of the literature, McCrae and Costa (1990) argued that "personality change is the exception rather than the rule after age 30; somewhere in the decade between 20 and 30, individuals attain a configuration of traits that will characterize them for years to come" (p. 10). Ten years later, two meta-analyses were published on the rank-order consistency (or differential stability) of personality traits. Roberts and DelVecchio (2000) reported that rank-order consistency increased with age, even in adulthood. They estimated that 30-and 40-year-olds would show 7-year retest correlations near .60, whereas individuals over age 50 would show retest correlations over . 70, and they concluded that recent generations have "stretched the time it takes to fully develop one's traits" (p. 18) past age 30. Curiously, another meta-analysis published the Correspondence concerning this article should be addressed to Antonio Terracciano, Box #03, Gerontology Research Center, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825. E-mail: terraccianoa@grc.nia.nih.gov.. Paul T. Costa, Jr., and Robert R. McCrae receive royalties from the Revised ...