Narcissism predicts heightened cortisol reactivity to a psychosocial stressor in men

Narcissists’ sensitivity to social evaluation should increase their physiological reactivity to evaluative stressors. However, very few studies have assessed the physiological correlates of narcissism. In this study, participants completed an evaluative laboratory stressor or a non-evaluative control task. Cortisol reactivity—a marker of the hypothalamic–pituitary–adrenal (HPA) axis stress response—and negative affect (NA) were higher in the stress versus control condition. However, men showed larger cortisol responses and, among men, higher narcissism scores predicted greater cortisol reactivity and larger increases in NA. Narcissism was unrelated to cortisol reactivity and NA among women and in the control condition. These findings highlight the influence of defensive personality traits on HPA reactivity and suggest a pathway through which narcissistic traits might influence long-term health outcomes.