Abstract Gray’s reinforcement sensitivity theory, consisting of the behavioral inhibition (BIS) and behavioral activation (BAS), is frequently used to represent basic dimensions of psychopathology. However, notably few investigations have examined the link between the BIS/BAS and symptoms of personality disorder (PD). Although the Fight-Flight-Freeze System has emerged in the revised model as an important aspect of motivation, the BIS (linked to anxiety) and BAS (linked to impulsivity) have been the primary foci. The current investigation uses a dimensional measure of PD, the schedule for nonadaptive and adaptive personality (SNAP; Clark, 1993) applied to two independent samples of English-speaking participants: undergraduates (n=276) and clinical patients (n=47). Results were consistent across both samples, demonstrating that symptoms of Cluster B PDs are indicative of high BAS levels whereas symptoms of Cluster C PDs are characterized by high BIS levels.