Testosterone, cortisol and the Dark Triad: Narcissism (but not Machiavellianism or psychopathy) is positively related to basal testosterone and cortisol

This research investigates endocrinological associations of the Dark Triad by relating narcissism, Machiavellianism and psychopathy to endogenous testosterone and cortisol. Building on the notion that narcissists (in contrast to individuals with a proneness to Machiavellianism or psychopathy) possess a preference for being superior and a propensity to dominate other individuals, it is assumed that the dominance-related hormone testosterone is positively associated with narcissism. It is additionally assumed that narcissism specifically is positively related to basal cortisol levels given narcissists' vigilance and sensitivity regarding their social esteem and status which is linked to cortisol activity. In a study including 129 men from the subclinical population (Mage = 21.97, range = 18 to 34 years), a positive correlation of narcissism with basal testosterone levels was found. Narcissism was also positively correlated with basal cortisol levels. No significant relations emerged for Machiavellianism or psychopathy. In sum, the present contribution suggests that dark personality traits, in this case narcissism, are expressed in the endocrinology of individuals.