Chapter 12: Personality Development Across the Lifespan

Researchers draw upon the established Big Five taxonomy—Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience—to structure the study of these traits across the lifespan. These domains are conceptually similar to dimensions of childhood temperament and are linked to fundamental neurobiological systems, such as the tie between Extraversion and incentive motivation or Conscientiousness and executive control systems. To fully grasp how personality evolves, various forms of consistency must be considered. Heterotypic stability refers to the coherence of an underlying trait even though its observable manifestations change with age, while homotypic stability evaluates consistency using the exact same measures across time. Within homotypic stability, four statistical types are examined: absolute stability (mean-level consistency), differential stability (rank-order consistency of individuals relative to one another), structural stability (similarity in the patterns of how traits covary), and ipsative stability (continuity in the profile or relative salience of traits within a person). Findings on absolute stability indicate that mean levels of traits change over time, notably showing increases in Agreeableness and Conscientiousness and decreases in Neuroticism, changes often interpreted as reflecting increased psychological maturity that facilitates the fulfillment of crucial adult social roles. The most significant period for these mean-level changes is young adulthood, not adolescence. The cause of these normative changes remains debated, contrasting the intrinsic maturational position with the life course perspective, which emphasizes that experiences associated with social roles—such as work or relationships—drive personality change. Regarding differential stability, rank-order consistency steadily increases across the lifespan, starting lower in childhood and peaking between the ages of fifty and seventy, thereby countering the historical claim that personality becomes entirely fixed by age thirty. Both stability and change are products of dynamic person-situation transactions. Stability is promoted by the corresponsive principle, which suggests that traits are reinforced when individuals elicit corresponding environmental responses, construe situations in consistent ways, and actively select environments that match their characteristics. Conversely, personality change is often catalyzed by major life "turning points"—like military service or marriage—which expose individuals to new reward and punishment structures, as well as by self-reflection, social learning, and the influence of others' perceptions, such as through the looking glass self-model.