Probing commitment in individuals with borderline personality disorder.

Interpersonal problems are a core symptom of borderline personality disorder (BPD). In particular, patients with BPD exhibit a heightened sensitivity to cues of acceptance or rejection in their relationships. The current study investigated the psychological processes underpinning this heightened responsiveness. In a between-subjects design, we implemented a reactivity induction designed to trigger either acceptance or rejection of a partner in two separate groups, and measured the effects which this manipulation had upon 49 patients with BPD, as well as 52 control participants. The experimental paradigm required participants to repeatedly choose whether to coordinate with their partner on a decision-making task. When both players coordinate on the same option, both are rewarded. The experiment probed participants' commitment to their partners: participants were sometimes presented with tempting opportunities to unilaterally defect from the coordination. The results show that participants in the BPD group were less committed than participants in the control group when exposed to the rejection manipulation.