Multidimensional Dichotomous Thinking Characterizes Borderline Personality Disorder
This study investigated whether dichotomous thinking is characteristic of borderline personality disorder (BPD). Patients with BPD (N = 16), control patients with Cluster-C personality disorder (PD; N = 12), and normal controls (N = 15) evaluated personalities from film clips in a structured response format. Film clips were presented with emotional themes, which were hypothesized to be either specific or nonspecific for borderline pathology, and with neutral themes. Dichotomous thinking was operationalized as the extremity of evaluations on a list of visual analogue scales (VASs) with bipolar trait descriptions. Patients with BPD made more extreme evaluations (dichotomous thinking) on BPD-specific film clips, but not on control film clips, than subjects of both control groups. The extreme evaluations of patients with BPD were not either “all good” or “all bad,” which indicates that patients with BPD do not engage in unidimensional good–bad thinking (splitting), but are capable of viewing others in mixed, although extreme, terms (multidimensional dichotomous thinking).