To ensure that the effects were not due to individuals experiencing acute inflammation, we ran two additional sets of analyses. First, we re-ran the correlations after excluding participants who had levels of IL-6 that were two standard deviations above the mean. The correlations between this truncated IL-6 variable and personality were virtually identical to the correlations on the entire sample. Second, because C-reactive protein measures more systemic inflammation than IL-6, we also tested whether personality was associated with this marker of inflammation. We examined Spearman correlations between personality and C-reactive protein, residualized for sex and age. Albeit with slightly weaker correlations, we replicated the basic findings for Neuroticism and Conscientiousness, as well as several of the facets, including N5: Impulsivity and C5: Self-Discipline (see Table 1).
