Trustworthiness judgments and Borderline Personality Disorder: an experimental study on the interplay of happiness and trustworthiness appraisals and the effects of wearing face masks during the Covid-19 pandemic in Germany

BACKGROUND: Judging positive emotional states or the trustworthiness of others is important for forming and maintaining social affiliations. Past studies have described alterations in these appraisal processes in Borderline Personality Disorder (BPD), which might have been exacerbated during the Covid-19 pandemic by the requirement to wear face masks. In the present study, we investigated in an online-survey a) whether social judgments are particularly strongly affected in individuals with BPD when they have to judge happiness and trustworthiness in facial stimuli covered by a mask, b) whether appraising a positive emotional state affects trustworthiness appraisals differentially in BPD and healthy individuals and c) whether social judgments are related to how individuals with BPD experience wearing masks during the pandemic. METHODS: Participants (67 HC, 75 BPD) judged happiness and trustworthiness of faces with calm expression with and without masks. Additionally, data on participants’ confidence in their judgments, the experience of the burden induced by wearing masks, the protective benefits of masks, and compliance to wearing masks were collected. RESULTS: Happiness and trustworthiness were evaluated less confidently and less intense in the BPD group compared to HC. Masks reduced happiness and trustworthiness ratings in both groups. Lower happiness appraisals contributed to lower trustworthiness appraisals except for those with BPD and low levels of symptom severity. Lower trustworthiness ratings were associated with a higher burden, attributing a lower benefit to masks and lower compliance with wearing masks in BPD. CONCLUSIONS: Masks do not exacerbate deficits in social judgments. However, lower trustworthiness appraisals in general were linked with more negative evaluations of wearing masks in the BPD group. TRIAL REGISTRATION: The aims and hypotheses were preregistered together with the design and planned analyses (https://aspredicted.org/f5du7.pdf). For findings of an additionally preregistered research question on the impact of adverse childhood experiences see supplementary material. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40479-022-00193-x.