Personality traits and mediating pathways to mortality risk: a systematic review

Objective: Personality traits have been regularly linked with all-cause mortality risk. However, what mechanisms may provide an indirect pathway from personality traits to mortality is unclear. We sought to systematically review the literature and provide an overview of the potential mechanisms that have been identified in the literature. Method: Five electronic databases (PubMed, Web of Science, CINAHL, PsycInfo, and PsycArticles) were searched from inception to January 27, 2023. From 611 studies initially identified, seven studies met the final inclusion criteria. These seven papers have a combined sample of 60,104 individuals (M = 8,585, SD =14,600; range 957–44,094). Results: These papers found that several variables, such as smoking, inflammation biomarkers, blood pressure, and sleep, mediated the relationship between various personality traits and mortality. There was considerable variation in the impact of results across cohorts, even when looking at similar variables, and notable differences in methodological approaches and reporting were discussed. Conclusions: This review identified a small pool of research looking at a range of indirect pathways (mediating variables). The review identified traits with well-established associations with mortality risk, such as neuroticism, do not have consistent findings in the mediation literature and a high level of variance in the degree to which mediators account for the personality–mortality relation between different cohorts. Despite these limitations, it is clear that examining indirect effects (mediation) has a crucial role to play in developing our understanding of the complex pathways that connect personality–mortality risk. We identify several avenues and considerations for future research.