Bilingual children have better Theory-of-Mind compared to monolingual children, but comparatively little research has examined whether this advantage in social cognitive ability also applies to adults. The current study investigated whether multilingual status and/or number of known languages predicts performance on a mentalizing task in a large sample of adult participants. Multilingualism was decomposed based on whether English is the first language or not. All analyses controlled for well-known predictors of mentalizing, such as gender, same-race bias, and years of English fluency. We found a U-shaped trend, such that monolinguals and multilinguals did not differ much in their mentalizing ability, but bilinguals performed worse than monolinguals. Our study builds upon past work by examining a large sample of participants, measuring a crucial aspect of adult social cognition that has previously been unexplored, controlling for several nuisance variables, and investigating whether multilingualism leads to additional benefits in mentalizing abilities beyond bilingualism.
