Neuroticism and introversion are associated with salivary cortisol patterns in adolescents

Previous studies have yielded equivocal findings on the relationship between personality and cortisol activity. The present study examined associations between personality and cortisol activity in a large, diverse adolescent sample, while partialling the effects of relevant demographic and health-retated covariates. A subsample of 230 participants (57% of whom reported elevated neuroticism) was selected from a larger sample of 16-18-year olds involved in a study on risk factors for emotional disorders. Subsample participants completed a battery of personality questionnaires, and saliva collection was requested several months later on three consecutive days at six time points per day, from wakeup to bedtime. Associations between personality and cortisol rhythms were examined using multilevel growth curve modeling. Neuroticism (N) and introversion (1) were significantly and differentially associated with features of diurnal cortisol patterns. Specifically, a significant N x gender interaction was observed, demonstrating flatter cortisol, rhythms across the waking day among mate participants with higher N. Elevated I, however, was associated with lower cortisol awakening responses for both mate and female participants, and higher cortisol at the time of waking for mate participants only. The present study supports personality as a significant predictor of diurnal cortisol patterns in late adolescence, after accounting for the effects of demographic and health covariates, and suggests that gender plays a role in moderating associations between personality and cortisol. (C) 2008 Elsevier Ltd. All rights reserved.