Low positive affect display mediates the association between borderline personality disorder and negative evaluations at zero acquaintance

Background Several recent studies have demonstrated that naïve raters tend to evaluate individuals with Borderline Personality Disorder (BPD) negatively at zero-acquaintance (i.e., in a ‘first impression’ type situation, where the rater has no knowledge of the individual and no prior interactions with them). Specifically, individuals with BPD were evaluated as less trustworthy, likeable, and cooperative than healthy participants (HCs). Based on previous impression formation studies, we hypothesized that the non-verbal cues positive affect display, negative affect display, and eye contact contribute to negative first impressions of those with BPD. Methods To address this question, we recruited 101 participants that rated the degree of positive affect display, negative affect display, and eye contact in 52 videos of age-and gender-matched BPD and HC participants. We hypothesized that low positive affect display, high negative affect display, and eye contact would mediate the association between group (BPD vs. HC) and ratings of trustworthiness, likeability, and cooperativeness. Results Ratings for positive affect display were significantly lower and those for negative affect display significantly higher for BPD versus HC targets, whereas eye contact did not differ significantly between groups. In multiple mediation models, positive affect display significantly mediated the association between group and trustworthiness/likeability, whereas negative affect display only mediated the association between group and likeability. None of the individual cues was a significant mediator of the association between group and cooperation. Conclusions We emphasize therapeutic possibilities to improve positive affect display –and thus overall first impressions– to increase the chances of forming social bonds for BPD individuals.