Personality in the age of industry: Structure, heritability, and correlates of personality in middle childhood from the perspective of parents, teachers, and children

- Personality in middle childhood coherent, heritable, and consequential.
- Specific details regarding personality at this age somewhat informant contingent.
- Children and teachers make less distinctions between certain personality traits.
- Self-ratings evidenced little heritability, unlike teacher and parent ratings.
- Teacher ratings more predictive of outcomes than self and parent ratings.

Middle childhood is a crucial juncture in the lifespan where children work toward achieving a sense of competence foundational for future development. However, middle childhood has historically been underrepresented in the personality literature. The current study provides a comprehensive examination of personality in middle childhood using a large (N = 2510), longitudinal sample of 10- to 12-year-old twins. The structure, heritability, and correlates of personality in this period were investigated using personality ratings of parents, teachers, and children. Results showed that personality in middle childhood has a coherent structure, is heritable, and is relevant for developmentally salient outcomes such as externalizing behavior, substance use, and academic engagement. Results emphasize the importance of investigating personality in middle childhood across multiple informants.