The present study aims to disentangle motivational and self-regulatory pathways to psychopathic traits in youth with severe antisocial behavior. The associations between self-reported psychopathic traits and indices derived from a laboratory measure assessing fear sensitivity and self-regulation were evaluated. Low scores on fear sensitivity and self-regulation were related to high scores on the self-reported Callous/Unemotional factor of psychopathic traits and the Callousness dimension in particular. The present study provides at least partial evidence for both motivational (low-fear hypothesis; Lykken, 1995) and self-regulatory (response modulation hypothesis; Patterson & Newman, 1993) accounts of psychopathic traits in youth.