A LONGITUDINAL FAMILY STUDY OF PERSONALITY-CHANGE AND STABILITY

The 19-year stability of personality from late adolescence to early ad ulthood was examined in a sample of 121 men and women who had particip ated in an earlier study of articulation and language development (Tem plin, 1966; Templin & Glaman, 1976). Personality was assessed using th e Eysenck Personality Inventory (EPI). At the time of retest, personal ity data were also collected from the participants' mothers. Modest st ability of individual differences in personality was observed, consist ent with the literature on longitudinal studies of personality during late adolescence and early adulthood. For the Extraversion and Neuroti cism scales, offspring means decreased significantly over the 19-year period such that the offspring means were closer to the mean scores of their mothers when they were followed up in adulthood as compared to their first testing in adolescence. There was, however, no change in m other-offspring resemblance from the initial test to retest. Mother-of fspring resemblance appears to be due largely to aspects of personalit y that were stable from adolescence to early adulthood. Implications o f these results are discussed in relation to the findings of previous longitudinal studies of adult personality and recent behavioral geneti c evidence regarding personality change and stability.