Importance of language for children’s theory of mind: Comparison of verbal and nonverbal theory of mind tasks

The ability to attribute mental states to oneself and others, known as the theory of mind (ToM), has been widely researched over the past 40 years, along with its relation to language comprehension. However, a majority of the research on the relation between ToM and language used only verbal tasks assessing false belief understanding as a measure of ToM. Therefore, this study aimed to analyze the relation between language and ToM, using a larger battery of ToM measures, with different language demands. A total of 203 typically developing children between 46 and 68 months of age, with average nonverbal cognitive skills, were assessed using language comprehension and ToM tasks. The language aspect was assessed using the Reynell Developmental Language Scales (Language Comprehension scale A). To assess ToM, verbal and non-verbal tasks were taken from the ToM subtest of the NEPSY?II. Results indicated a significant correlation between language comprehension and verbal and non-verbal ToM measures. Hierarchical regression showed that language comprehension was a significant predictor for children?s performance on both verbal and non-verbal ToM tasks. Specifically, language comprehension affected ToM, regardless of the language demands of the ToM tasks. However, language comprehension was a stronger predictor for verbal than non-verbal ToM tasks. The results of this study contribute to the view that the relation between language and ToM is fundamental and exceeds the features of specific tasks.