Howard S. Friedman

A lifespan perspective on personality and health uncovers new causal pathways and provides a deeper, more nuanced approach to interventions. It is unproven that happiness is a direct cause of good health or that negative emotion, worry, and depression are significant direct causes of disease. Instead, depression-related characteristics are likely often reflective of an already-deteriorating trajectory. It is also unproven that challenging work in a demanding environment usually brings long-term health risks; on the contrary, individual strivings for accomplishment and persistent dedication to one's career or community often are associated with sizeable health benefits. Overall, a substantial body of recent research reveals that conscientiousness plays a very significant role in health, with implications across the lifespan. Much more caution is warranted before policy makers offer narrow health recommendations based on short-term or correlational findings. Attention should be shifted to individual trajectories and pathways to health and well-being.

Conscientiousness has been shown to predict healthy behaviors, healthy social relationships, and physical health and longevity. The causal links, however, are complex and not well elaborated. Many extant studies have used comparable measures for conscientiousness, and a systematic endeavor to build cross-study analyses for conscientiousness and health now seems feasible. Of particular interest are efforts to construct new, more comprehensive causal models by linking findings and combining data from existing studies of different cohorts. Although methodological perils can threaten such integration, such efforts offer an early opportunity to enliven a life course perspective on conscientiousness, to see whether component facets of conscientiousness remain related to each other and to relevant mediators across broad spans of time, and to bolster the findings of the few long-term longitudinal studies of the dynamics of personality and health. A promising approach to testing new models involves pooling data from extant studies as an efficient and heuristic prelude to large-scale testing of interventions.

Personality traits can be employed to guide understanding of trajectories to health and longevity, but long‐term longitudinal study and multifaceted assessment of healthy aging are crucial. Following up on the life span study initiated by Lewis Terman, we assessed 4 validated factors of personality in young adulthood in 1940, constructed a multifactor measure of participants' healthy aging in 1986, and collected death certificates through 2007 (to determine longevity) on a sample of 1,312 Terman participants (732 men). Neuroticism predicted worse physical health and subjective well‐being in old age and, for women, higher mortality risk, but for men, neuroticism predicted decreased mortality risk. For both sexes, extraversion predicted old‐age social competence, whereas conscientiousness predicted men's old‐age productivity. Differential patterns of association between personality traits and healthy aging components are informative about individual personality characteristics and long‐term health outcomes.