The link between the factuality of verb and the theory of mind ability of Mandarin‐speaking children with high‐functioning autism

Weak theory of mind (ToM) ability is a core deficit in children with autism. A growing body of work has found that there is a close relation between complement syntax and ToM in autistic children. However, researchers have not yet investigated whether other linguistic components may explain the difficulties in ToM reasoning in autistic children.To determine whether verb factuality (i.e., mental and action verbs) is related to ToM ability, as measured by a false belief understanding (FBU) task after controlling the effect of complement syntax for Mandarin-speaking autistic children.Participants were verbal autistic children, aged 4-7 years. Their IQ performance (verbal, performance and total IQ) and the comprehension of complement syntax were evaluated. A total of 38 children scoring over 9 points in complement syntax test and 90 points in the verbal IQ test were selected to complete verb factuality and FBU task. The χ2 tests and correlation analyses were carried out on two relations: (1) ToM ability and understanding of verb factuality; and (2) ToM ability and comprehension of complement syntax.A total of 11 autistic children completed the action verb factuality task, while 14 completed the mental verb factuality task and 13 completed both tasks. Participants performed well on the verb factuality task, and their ToM performance appeared to be related to their linguistic ability, regardless of the type of verb (i.e., action or mental verb). However, complement syntax scores did not significantly predict the success of the FBU task for the autistic children.The results of this study link weaker ToM ability with the understanding of verb factuality among autistic children aged 4-7 and provide new evidence for the view that the development of language facilitates improvement of ToM skills. The findings shed new light on how language affects or determines social interactions.What is already known on the subject ToM ability is crucial for social interaction. It has been claimed that mental verb factuality (e.g., think, had thought) may play a role in the development of ToM reasoning in typically developing children, but whether there is a link between the mastery of verb factuality and ToM skills in autistic children is still unclear. What this study adds to existing knowledge Correlational analysis revealed links between verbal ToM measured by unexpected location task and factuality test of mental verbs as well as action verbs. More importantly, this study confirmed the extra role of verb factuality in explaining ToM ability after excluding the influence of the complement syntax. What are the potential or actual clinical implications of this work? This study suggests that the factuality of verbs could serve as a tool for autistic children to infer the mental states of others. Thus, training on this linguistic structure could be taken into consideration when improving the social skills of autistic children.