• Psychopathy;
  • Aversive conditioning;
  • Skin conductance;
  • Psychopathic Personality Inventory-Revised;
  • Fearlessness


The role of the two dimensions of psychopathy—dispositional fearlessness (theorized to reflect variations in reactivity of the brain's defensive system) and externalizing proneness (presumed to reflect variations in function of anterior regulatory systems)—in fear learning was examined in a sample of undergraduates assessed using the Psychopathic Personality Inventory-Revised (PPI-R) who participated in a differential aversive conditioning task. Only scores on self-reported “fearless dominance,” irrespective of scores on “impulsive antisociality,” were related to diminished acquisition of physiological fear. Consistent with dual-process accounts of psychopathy proposing divergent etiological pathways for the interpersonal/affective and the social deviance features of the disorder, our results lend support to the existence of a deficit in reactivity of the brain's defensive system underlying the fearlessness dimension of psychopathy.