Constance J. Jones

Personality Change Over 40 Years of Adulthood: Hierarchical Linear Modeling Analyses of Two Longitudinal Samples

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.

The growing evidence for personality change in adulthood: Findings from research with personality inventories

Theories of adult development all agree that adulthood is a time of important changes in goals, resources, and coping. Yet, impressed with the rank-order stability of individual differences in personality, many researchers interested in personality traits and personality assessment doubt that personality changes in meaningful and systematic ways during adulthood. This article reviews large studies of mean-level change in personality characteristics measured with broad-band personality inventories, and includes both cross-sectional and cross-cohort longitudinal research. The results show considerable generalizability across samples, cohorts, and studies. In particular, people score higher with age on characteristics such as conscientiousness, agreeableness, and norm-adherence, and they score lower with age on social vitality. These findings provide evidence that personality does change during adulthood and that these changes are non-negligible in size, systematic, not necessarily linear, and theoretically important.

Longitudinal Hierarchical Linear Modeling Analyses of California Psychological Inventory Data From Age 33 to 75: An Examination of Stability and Change in Adult Personality

Twenty aspects of personality assessed via the California Psychological Inventory (CPI; Gough & Bradley, 1996) from age 33 to 75 were examined in a sample of 279 individuals. Oakland Growth Study and Berkeley Guidance Study members completed the CPI a maximum of 4 times. We used longitudinal hierarchical linear modeling (HLM) to ask the following: Which personality characteristics change and which do not? Five CPI scales showed uniform lack of change, 2 showed heterogeneous change giving an averaged lack of change, 4 showed linear increases with age, 2 showed linear decreases with age, 4 showed gender or sample differences in linear change, 1 showed a quadratic peak, and 2 showed a quadratic nadir. The utility of HLM becomes apparent in portraying the complexity of personality change and stability.

Developmental paths of psychological health from early adolescence to later adulthood.

Developmental paths of psychological health were examined for 236 participants of the Berkeley Growth Study, the Berkeley Guidance Study, and the Oakland Growth Study. A clinician-reported aggregate index, the Psychological Health Index (PHI), based on California Q-Sort ratings, was created for subsets of participants at 14, 18, 30, 40, 50, and 62 years of age. Latent curve analysis was then used to explicate the life span development of psychological health. Psychological health development could be successfully modeled via 2 piecewise latent growth curves. Psychological health appears to be stable in adolescence and to steadily increase from 30 to 62 years of age. A moderately strong positive correlation between the 2 developmental curves indicates that those with greater psychological health in adolescence show more improvement in adult psychological health tend to also. Results illustrate the value of the PHI and the power of latent curve analysis to explicate longitudinal stability and change.

Predicting Personality Stability Across the Life Span: The Role of Competence and Work and Family Commitments

Longitudinal studies suggest modest continuity in personality from adolescence to early adulthood and greater continuity over successive periods during the adult years. However, individual differences in personality stability do exist. We discuss potential sources of personality change, especially as they relate to development, role assumption and commitment, and loss of roles and commitments. Then, using data from the Intergenerational Studies, we employ measures of competence and of work and family commitments, assessed both in high school and adulthood, to predict personality stability from high school to early and late adulthood. Results indicate that personality stability can be successfully predicted with such measures. Greater personality stability is found for those determined to be more “planfully competent,” but additional family and work role variables also increase predictive power, in some instances. Using two alternate measures of competence—one from the California Q-sort and the other from the California Psychological Inventory—we replicated the finding that men with more disorderly careers show less personality stability, and that women who have experienced more divorces show less personality stability.

Personal warmth and psychological health at midlife

Personal warmth, arguably a strong trait in the makeup of psychological health, seems to fade in conceptual importance at midlife. In contrast, ideas of interiority and androgyny appear to gain conceptual importance at midlife. The present study sought to rebalance these foci by determining the predictive power of personal warmth for psychological health of men and women at age 50: first, by developing separate California Psychological Inventory (CPI) scales to assess personal warmth; next, by joining these warmth scales with the 20 standard CPI scales to predict psychological health. Without the personal warmth scale, the standard CPI scales do not significantly predict psychological health for men; for women, the standard scales do. For both genders, the personal warmth scales add significantly to the predictability of psychological health. The results point to an amendment of current theoretical formulations of interiority and androgyny to better understand optimal psychological development in men and women at midlife.