Despite the inherent limitation of a cross-sectional assessment, the present study had several strengths, including a large community sample that ranged across most of the lifespan and a comprehensive measure of personality that covered the facets, as well as the five major dimensions, of personality. Our sample, however, was derived from a rural area in Sardinia, which differs in several respects from more metropolitan areas. Despite lifestyle differences and fewer economic opportunities, personality traits in this sample do not differ from personality measured in other Italian samples (Costa et al. 2007). The present research moves beyond the typical self-reported health ratings to identify a critical medical biomarker associated with personality. Interestingly, our findings for this physiological marker mirror those typically observed for self-reported health-related outcomes: Individuals with the combination of high Neuroticism and low Conscientiousness are particularly vulnerable to elevated levels of this inflammatory cytokine. Identifying such biomarkers will help to elucidate the physiological mechanisms that link personality traits and physical health.
