Stability and change in personality traits from late adolescence to early adulthood: a longitudinal twin study

Abstract

We conducted a longitudinal-biometric study examining stability and change in personality from ages 17 to 24 in a community sample of male and female twins. Using Tellegen's (in press) Multidimensional Personality Questionnaire (MPQ), facets of Negative Emotionality (NEM) declined substantially at the mean and individual levels, whereas facets of Constraint (CON) increased over time. Furthermore, individuals in late adolescence who were lowest on NEM and highest on CON remained the most stable over time, whereas those exhibiting the inverse profile (higher NEM, lower CON) changed the most in a direction towards growth and maturity. Analyses of gender differences yielded greater mean-level increases over time for women as compared to men on facets of CON and greater mean-level increases for men than women on facets of Agentic Positive Emotionality (PEM). Biometric analyses revealed rank-order stability in personality to be largely genetic, with rank-order change mediated by both the nonshared environment (and error) as well as genes. Findings correspond with prior evidence of a normative trend toward growth and maturity in personality during emerging adulthood.

Figure 1

A path diagram of an AE Cholesky model for Well-being (WB) at Time 1 (T1) and Time 2 (T2). For the sake of parsimony, shared environmental effects were omitted from this diagram, and the paths are only shown for one member of a twin pair. In this model the variance at each time point is decomposed into additive genetic (A₁, A₂,) and nonshared environmental effects (E₁, E₂). a₁₁ & e₁₁ = paths representing additive genetic and nonshared environmental contributions to the Time 1 phenotype, respectively; a₂₁ & e₂₁ = paths representing additive genetic and nonshared environmental contributions from Time 1 to the Time 2 phenotype, respectively; a₂₂ & e₂₂ = paths representing additive genetic and nonshared environmental contributions unique to the Time 2 phenotype, respectively. These paths are squared to estimate the proportion of variance accounted for by additive genetic and nonshared environmental influences.

Figure 2

MPQ personality profiles for groups exhibiting varying levels of reliable change over time. Mean T-scores at age 17 are depicted for all MPQ primary scales separated into five groups ranging from those exhibiting no reliable change from ages 17 to 24 to those exhibiting reliable change on seven or more scales. We conducted univariate ANOVAs to test for significant differences between the groups in mean levels of each trait. Well-being, F(4, 905) = 2.57, p<.05; Social Potency, F(4, 905) = 1.34, ns; Achievement, F(4, 905) = 0.64, ns; Social Closeness, F(4, 905) = 3.18, p<.05; Stress Reaction, F(4, 905) = 16.48, p<.05; Alienation, F(4, 905) = 13.37, p<.05; Aggression, F(4, 905) = 13.68, p<.05; Control, F(4, 905) = 10.69, p<.05; Harm Avoidance, F(4, 905) = 6.15, p<.05; Traditionalism, F(4, 905) = 7.99, p<.05; Absorption, F(4, 905) = 6.71, p<.05. F-tests remained significant after controlling for gender.