Oxytocin administration and emotion-related startle in psychopaths : a yawn and startle study.

Abstract

Psychopathy is characterized by a general antisocial lifestyle with behaviors including being selfish, manipulative, impulsive, fearless, callous, possibly domineering, and particularly lacking in empathy. Contagious yawning in our species has been strongly linked to empathy. We exposed 133 students, male and female, who completed a self-report Psychopathic Personality Inventory (Revised), to a yawning paradigm intended to induce a reactionary yawn. Further, we exposed males to an emotion-related startle paradigm meant to assess peripheral amygdalar reactivity. We found that those at or above clinical levels of the PPI - R subscale Coldheartedness were significantly less likely to yawn, χ2(1, N = 123) = 7.051, p = .008. Other subscales were not significant. Further, we found that difference scores in peak amplitudes between Negative and Neutral stimuli in the startle paradigm were predictive of frequency of yawning (β =-.383, p =.007). These data suggest that psychopathic traits may be strongly related to the empathic nature of contagious yawning in our species.