Effects of interaction partner on theory of mind measurement in clinical and non-clinical samples

Objective: Theory of Mind (ToM)—the ability to infer others’ mental states—is influenced by social group membership and the similarity of mental states. Since perceivers presumably rely more strongly on their own perspective when evaluating individuals from their own (vs. other) social group, ToM is reduced for same-group targets with conflicting mental states (vs. similar mental states). Method: ToM was assessed with the Movie for the Assessment of Social Cognition (MASC) in 103 patients with alcohol use disorder, 126 with personality disorders, and 32 non-clinical participants. A logistic linear mixed model tested effects of sender, receiver, and patient gender on ToM scores. Results: Across samples, ToM scores were lower when participants and targets shared the same gender. In clinical groups, male targets elicited higher ToM scores than female ones. Conclusions: Interaction partners’ gender significantly moderated ToM performance, highlighting the need to consider gender composition in ToM measures.