The structure, development, and correlates of individual differences in human personality

Abstract

Human personality possesses a complex psychometric structure that changes with maturation and predicts a number of important life outcomes. The current dissertation presents four studies that track the structure, development, and correlates of personality, primarily through a behavioral genetic lens. Study 1 finds that the genetic and environmental structure of personality domains residing over more narrow facets is more complex than can be accounted for by simple, broad domains. Study 2 presents meta-analytic evidence for the differential stability of personality traits across the lifespan, as well as genetic and environmental contributions to stability. Personality traits become more stable with age, and this trend is primarily driven by increasing environmental sources of stability. Study 3 details a transactional model of parental educational expectations, child academic behaviors, and child academic achievement across early development. Finally, Study 4 presents associations between state-level aggregates of personality and the level, timing, and context of fertility across the United States. Together, these studies indicate the importance of understanding personality for individual-level and population-level processes, as well as, the complexities of this goal due to the dynamic nature of gene-environment dependencies that undergird personality development.