Personality Plasticity After Age 30 Antonio

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 metaanalyses 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 30and 40-year-olds would show 7-year retest correlations near .60, whereas individuals older than age 50 would show retest correlations more than .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 same year (Ardelt, 2000) concluded that rank-order consistency increased up to age 50 but decreased thereafter. Meta-analyses combine data from different instruments, samples, and historical times and may be subject to confounds (e.g., studies of 30-year-olds may have used less reliable instruments than studies of 60-year-olds). An alternative approach would examine rank-order stability in different age groups using the same instrument administered to comparable samples over the same time interval and in the same historical period. Such a design was used by Costa, McCrae, and Arenberg (1980), who examined 6and 12-year retest coefficients for GuilfordZimmerman Temperament Survey (GZTS; Guilford,