Deficient fear conditioning and self-reported psychopathy: the role of fearless dominance.

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.