BackgroundPatients with borderline personality disorder (BPD) show negative and unstable self- and other-evaluations compared to healthy individuals. It is unclear, however, how they process self- and other-relevant social feedback. We have previously demonstrated a positive updating bias in healthy individuals: When receiving social feedback on character traits, healthy individuals integrate desirable more than undesirable feedback. Here, our aim was to test whether BPD patients exhibit a more negative pattern of social feedback processing.MethodWe employed a character trait task in which BPD patients interacted with four healthy participants in a real-life social interaction. Afterwards, all participants rated themselves and one other participant on 80 character traits before and after receiving feedback from their interaction partners. We compared how participants updated their ratings after receiving desirable and undesirable feedback. Our analyses included 22 BPD patients and 81 healthy controls.ResultsHealthy controls showed a positivity bias for self- and other-relevant feedback as previously demonstrated. Importantly, this pattern was altered in BPD patients: They integrated undesirable feedback for themselves to a greater degree than healthy controls did. Other-relevant feedback processing was unaltered in BPD patients.ConclusionsOur study demonstrates an alteration in self-relevant feedback processing in BPD patients that might contribute to unstable and negative self-evaluations.