The interrelations of childhood conscientiousness, nonindependent and independent adversity, and adult physical health

Abstract

Researchers have urged a lifespan approach to health promotion, intervening at earlier stages in life in order to shape physical health across time (Shonkoff et al., 2009). Intriguing findings suggest that the personality trait conscientiousness in childhood predicts physical health later in adulthood. Unfortunately, pathways linking personality to health are not well understood, requiring further elucidation before developing interventions that target conscientiousness as a strategy for promoting later health (Friedman et al., 2014). The present study addressed several gaps in the literature, testing models in which personality and health were measured at multiple time points; testing mediation effects of personality on later health; the joint effects of childhood conscientiousness and childhood/adolescent independent and nonindependent adversity exposure on health; whether conscientiousness moderates the influence of adversity on heath; and the role of childhood conscientiousness on health outcomes in an earlier period in adulthood than is typically examined. Data were drawn from a longitudinal study of 205 families, focused on students attending urban elementary schools who were followed for 20 years into young adulthood. Multimethod and well-validated measures of personality, adversity, and physical health were derived from interviews and questionnaires with participants, parents, and teachers. Models were tested separately for two different age 30 health outcomes in young adulthood – body mass index (BMI), and a latent variable indexing health status, based on three indicators: self-rated health, functional impairment, and sum of lifetime illnesses. Results indicated that higher childhood conscientiousness predicted lower young adult BMI, even after consideration of childhood health, the emerging adulthood personality trait of constraint measured at age 20, adversity across childhood and adolescence, age, and sex. Across both models, emerging adulthood constraint did not directly predict young adult BMI or health status, and did not mediate effects of conscientiousness assessed in childhood on either young adult health outcome. Nonindependent adversity (experiences likely influenced by a person’s own behavior) predicted young adult health status but not young adult BMI. Personality did not moderate the effects of adversity on either young adult health outcome. Some support was found consistent with the possibility that nonindependent adversity in adolescence mediates the relationship between childhood conscientiousness and young adult health status, but results are inconclusive. Findings highlight the potentially unique importance of conscientiousness in childhood for health 20 years later in young adulthood. Limitations and implications of these results for illuminating complex models linking personality, adversity, and health over the earlier decades of the lifespan are discussed, as well as the possibility that childhood conscientiousness may be a target for interventions to promote adult physical health.