Weight bias often results in the social exclusion of individuals with obesity. The direct, short-term psychological effects of social exclusion in obesity have not been investigated yet. This study experimentally tests whether social exclusion elicits stronger negative emotions in individuals with obesity compared to normal-weight controls. Specifically, we test whether social exclusion has a specific impact on shame. In total, N=299 individuals (n=130 with body mass index [BMI]≤30 and n=169 with BMI>30) were randomly assigned to a social exclusion condition or a control condition that was implemented with an online Cyberball paradigm. Before and after, they filled out questionnaires assessing state emotionality. social exclusion increased negative emotionality in both groups compared to the control condition (p<0.001) according to a multivariate ANOVA. However, the interaction of group and social exclusion was also significant (p=0.035) and arose from a significant, specific increase of shame in the group with obesity during social exclusion (p<0.001, Cohen's d=0.7). When faced with social exclusion, individuals with obesity do not respond with more intensive negative emotions in general compared to controls, but with a specific increase in shame. As social exclusion is frequent in individuals with obesity, psychological interventions focussing shame-related emotional distress could be crucial.
