Variability of theory of mind versus pragmatic ability in typical and atypical development

Introduction: Numerous studies have linked deficits in Theory of Mind (ToM) with language problems. We aimed to explore the similarities and differences between children's patterns of performance on a ToM task that requires minimal linguistic skill and a pragmatic inference task that relies on both ToM and language. We assessed variability in pragmatic inference skills and ToM across populations of children (8-14 years) displaying varying cognitive profiles. We further compared the sensitivity of ToM versus pragmatic ability to core language skills, memory and executive functioning (EF). Method: ToM was tested using the Social Attribution Task (SAT-MC-II). Pragmatic ability was assessed in an implicature comprehension task. Receptive vocabulary, grammar comprehension, short-term and working memory (STM and WM) capacity and EF were measured using Hungarian adaptations of standard tasks and tests developed by the authors' lab. In addition to typically developing (TD) children (n = 33), we included children with neurodevelopmental disorders where ToM and/or language abilities are vulnerable: autism spectrum disorder (ASD, n = 26), attention deficit hyperactivity disorder (ADHD, n = 25) and developmental language disorder (DLD, n = 18). Results: Results revealed a significant but only moderate positive correlation between pragmatic inference and ToM indicating that the two abilities are related but distinct. The ASD group showed impairments in both ToM and pragmatic inference ability but no significant deficit was observed in ADHD or DLD relative to TD children in either skill. However, while SAT-MC-II results were only affected by verbal WM and vocabulary measures, pragmatic performance was associated with STM, verbal WM, EF, grammatical skills and vocabulary. Conclusion: Our findings indicate that disentangling the contributions of different cognitive skills to ToM tasks may help clarify the role of ToM in language skills and identify distinct patterns of ToM and pragmatic skills in developmental disorders.