Individual difference variables,affective differentiation,and the structures of affect

Methodological arguments are usually invoked to explain variations in the structure of affect. Using self-rated affect from Italian samples (N=600), we show that individual difference variables related to affective differentiation can moderate the observed structure. Indices of circumplexity and congruence coefficients to the hypothesized target were used to quantify the observed structures. Results did not support the circumplex model as a universal structure. A circular structure with axes of activation and valence was approximated only among more affectively differentiated groups: students and respondents with high scores on Openness to Feelings and measures of negative emotionality. A different structure, with unipolar Positive Affect and Negative Affect factors, was observed among adults and respondents with low Openness to Feelings and negative emotionality. The observed structure of affect will depend in part on the nature of the sample studied.     

Personality plasticity after age 30

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 for periods of up to 42 years. Consistency declined toward a nonzero 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, also was unrelated to age. These data strengthen claims of predominant personality stability after age 30.     

Hierarchical linear modeling analyses of the NEO-PI-R scales in the Baltimore Longitudinal Study of Aging

The authors examined age trends in the 5 factors and 30 facets assessed by the Revised NEO Personality Inventory in Baltimore Longitudinal Study of Aging data (N=1,944; 5,027 assessments) collected between 1989 and 2004. Consistent with cross-sectional results, hierarchical linear modeling analyses showed gradual personality changes in adulthood: a decline in Neuroticism up to age 80, stability and then decline in Extraversion, decline in Openness, increase in Agreeableness, and increase in Conscientiousness up to age 70. Some facets showed different curves from the factor they define. Birth cohort effects were modest, and there were no consistent Gender x Age interactions. Significant nonnormative changes were found for all 5 factors; they were not explained by attrition but might be due to genetic factors, disease, or life experience.     

Personality trait development from age 12 to age 18: longitudinal,cross-sectional,and cross-cultural analyses

Three studies were conducted to assess mean level changes in personality traits during adolescence. Versions of the Revised NEO Personality Inventory (P. T. Costa, Jr., & R. R. McCrae, 1992a) were used to assess the 5 major personality factors. A 4-year longitudinal study of intellectually gifted students (N = 230) was supplemented by cross-sectional studies of nonselected American (N = 1,959) and Flemish (N = 789) adolescents. Personality factors were reasonably invariant across ages, although rank-order stability of individual differences was low. Neuroticism appeared to increase in girls, and Openness to Experience increased in both boys and girls; mean levels of Extraversion, Agreeableness, and Conscientiousness were stable. Results extend knowledge of the developmental curve of personality traits backward from adulthood and help bridge the gap with child temperament studies.     

An alternative to the search for single polymorphisms: toward molecular personality scales for the five-factor model

There is growing evidence that personality traits are affected by many genes, all of which have very small effects. As an alternative to the largely unsuccessful search for individual polymorphisms associated with personality traits, the authors identified large sets of potentially related single nucleotide polymorphisms (SNPs) and summed them to form molecular personality scales (MPSs) with from 4 to 2,497 SNPs. Scales were derived from two thirds of a large (N = 3,972) sample of individuals from Sardinia who completed the Revised NEO Personality Inventory (P. T. Costa, Jr., & R. R. McCrae, 1992) and were assessed in a genomewide association scan. When MPSs were correlated with the phenotype in the remaining one third of the sample, very small but significant associations were found for 4 of the 5e personality factors when the longest scales were examined. These data suggest that MPSs for Neuroticism, Openness to Experience, Agreeableness, and Conscientiousness (but not Extraversion) contain genetic information that can be refined in future studies, and the procedures described here should be applicable to other quantitative traits.     

Incipient adult personality: The NEO‐PI‐3 in middle‐school‐aged children

This study administered the NEO Personality Inventory‐3 (NEO‐PI‐3), a more readable version of an adult measure of the Five‐Factor Model, to 449 boys and girls aged 12 and 13, who described themselves or a peer. Analyses of readability, reliability, factor structure, and convergent and discriminant validity suggested that the NEO‐PI‐3 can be appropriately used in this age group. Personality traits in children of this age closely resemble in structure and functioning the traits of older adolescents and adults. Most gender differences known from studies of adults are found in this age group, and mean levels show continuity with older groups. The NEO‐PI‐3 appears to be a useful instrument for research, and potentially for clinical applications, in middle‐school‐aged children.