Emotions at the border: Increased punishment behavior during fair interpersonal exchanges in borderline personality disorder.

This study evaluated whether the impairment in cooperation that characterizes individuals with borderline personality disorder (BPD) can be explained by the difficulty to use emotion regulation strategies and to accurately perceive the fairness of others' behavior. Forty-one patients with BPD and 41 sex and age matched healthy controls (HC) played the responder's role in a Modified Ultimatum Game during which they were asked to apply 3 different emotion regulation strategies: look, distancing, and reappraisal. Offer rejection rates were used as an index of punishment behavior. After the experiment, participants also rated the degree of perceived equity of the offers after receiving fair and unfair offers. Reappraisal was effective in decreasing punishment behaviors for unfair offers in both the BPD and HC groups. By contrast, BPD patients displayed a different behavior than HC when making decisions upon fair offers, independently from the regulation strategies adopted. In fact, they rejected higher rates of fair offers than HC. Further, BPD patients judged fair offers as less fair than HC. This indicates an altered judgment and decision making on fair interpersonal exchanges. In conclusion, BPD patients exhibit increased punishment behavior during fair, "favorable" social exchanges, which they tend to perceive as less fair than controls. Thus, BPD patients may be biased toward underestimating positive feedback from others. (PsycINFO Database Record (c) 2019 APA, all rights reserved).