Young individuals with BPD do not learn they are liked and show altered self-esteem reactivity to social feedback

Background: In today’s social media–driven world, adolescents and young adults face constant exposure to peer feedback which affects their self-image. This study investigates how social feedback influences self-esteem in adolescents and emerging adults with elevated borderline personality (BPD) symptoms, a vulnerable group characterized by low self-esteem and a negative, unstable self-image. Methods: We employed a social evaluation task simulating a social media context. Participants were asked to make social predictions (whether they expected Likes or Dislikes from peers), received social feedback (Likes or Dislikes from peers) and repeatedly reported their momentary self-esteem. The sample included 55 adolescents and emerging adults with BPD symptoms and 67 matched non-clinical controls (NCC, ages 13-25). Computational reinforcement learning modeling was used to analyze their behavior. Results: Compared to NCC, BPD showed strongly biased negative expectations of not being liked by others. Besides, computational modeling revealed significant group differences in social learning: individuals with BPD symptoms failed to learn from frequent positive social feedback (Likes) but overweighted rare negative social feedback (Dislikes) received from generally benevolent peers. Moreover, their self-esteem was disproportionately reactive to positive feedback from critical raters, a pattern partly explained by individual differences in self-reported adverse family experiences. Conclusions: These findings highlight fundamental disruptions in how young people with BPD symptoms learn from social feedback and how they use it to inform their self-esteem.