Cooperative decision-making in borderline personality disorder: insights from a preregistered study using a...

Social decision-making poses challenges for individuals with Borderline Personality Disorder (BPD), which can lead to maladaptive interpersonal functioning. Although previous research on cooperative decisions in BPD has produced mixed findings, studies examining different aspects of cooperative behavior suggest that individuals with BPD may specifically show reduced reactive cooperation, while their active cooperation appears similar to that of healthy individuals.

To address these mixed results, we used a comprehensive battery of economic tasks in this preregistered study to assess different aspects of cooperation in 35 women with BPD and 50 healthy women.

Consistent with our expectations, there were no significant differences between groups in active cooperation within the Dictator Game. However, contrary to our hypotheses, neither BPD status nor dissociality scores were related to reactive cooperation in the Ultimatum Game. To synthesize findings across studies, a mini meta-analysis was conducted, revealing no significant overall effect of group membership on rejection rates in the Ultimatum Game. Additionally, women with BPD showed similar social preferences, fairness perceptions and inequality aversion as the control group.

These results suggest that in the context of anonymous, one-shot economic games, individuals with BPD may not differ from healthy individuals in terms of cooperative behavior. This highlights the importance of using baseline variants of standard economic tasks when considering contextual factors that affect social behavior in BPD.