In this chapter I focus on the nature and bases of emotional deviation in psychopathy and describe how new concepts and methods in the field of emotion science have been used to extend understanding of different facets of the psychopathy construct. A dual-process model of psychopathy is proposed in which the core affective–interpersonal symptoms of psychopathy, emphasized by Cleckley (1941, 1976) in his classic treatise, are posited to reflect an underlying etiologic mechanism distinct from that associated with chronic antisocial deviance (“externalizing”).