This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors ofmortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HR<1.00) for openness, and U.S. studies showed a pattern of protective effects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability andreproducibility, especially for aging-related longitudinal research.

One of the forces underlying the increased use of secondary data is a growing division of labor among scholars, a process that has taken place in many other fields. For example, the scientific staff of a particle accelerator includes physicists who vary greatly in skills and specialization. Although the physical sciences were the first to experience a high degree of division of labor, it is now common in the biological and medical sciences as well. For instance, the Human Genome Project was composed of multidisciplinary research teams, as are many clinical trials. More often than not, data from these large-scale projects in physics, genetics, and medicine follow the pattern of one set of scientists collecting data (and perhaps conducting and publishing some initial analyses) and then making these data publicly available, with other sets of scientists engaging in secondary analyses that are often more in-depth and complex. This kind of research is quickly beginning to characterize research in the social and behavioral sciences, and in particular, social scientific research in adult development and aging. In this chapter, we discuss these increasingly important breakdowns of roles and what they mean for adult development and aging research in the social and behavioral sciences.

The current study investigated whether personality traits and facets predicted levels of Interleukin-6, C-reactive protein, and Fibrinogen and whether physical activity mediated the relationship between personality and these biomarkers of health. High harm avoidance and low neuroticism were associated with elevated IL-6, while high social potency, high control, and low achievement were associated with elevated FGN. Mediation models suggested that physical activity mediated the association between higher levels of achievement and lower IL-6. Physical activity is an important factor in the health behavior model, and explains some of the associations between personality and downstream inflammation.

Personality is associated consistently with mortality hazards, but the physiological pathways are not yet clear. Immune system dysregulation may be one such pathway due to its role in age-related morbidity and mortality. In this preregistered study, we tested whether interleukin-6 (IL-6) and C-reactive protein (CRP) mediated the associations between personality traits and mortality hazards. The present sample were 957 participants from the Midlife in the United States Survey that had 14 years of follow-up. Higher conscientiousness was associated with reduced mortality hazards, with each one standard deviation increase in conscientiousness associated with a 35% lower mortality risk. IL-6, but not CRP, partially mediated this association, with IL-6 accounting from 18% of this association in the fully adjusted model. There was not robust evidence that the biomarkers mediating the other four traits and mortality. Taken together, higher conscientiousness may lead to a longer life partially as a result of lower IL-6.