Sex differences in psychopathic traits during early adolescence: The role of heart rate

Abstract

Purpose: Psychopathy – a condition associated with early, pervasive, and severe antisocial behaviors – has been found to be relatively stable over the life-course. While studies have documented a consistent sex difference in psychopathy, the explanatory mechanism is unclear. Methods: Using a sample of 452 youth (Mage = 11.92 years, 49.6% female), this study empirically tests whether lower heart rate during a social stress task could serve as a causal mechanism to explain the sex difference in psychopathic traits as measured by the Antisocial Process Screening Device. Results: Results support prior evidence that males exhibit lower heart rates than females and that lower heart rate is associated with higher levels of psychopathy. However, heart rate during a stressor does not sufficiently explain the sex difference in psychopathic traits overall, although it seems to partially explain the sex difference in impulsivity, a key behavioral component of psychopathy. Discussion: The findings suggest that more research is needed to understand how sex differences in psychopathy emerge in early life and encourages further research on the age(s) or developmental stages at which low heart rate – a well-replicated biological correlate of antisociality – is relevant to understanding the etiology of psychopathy and other antisocial behaviors.