Background: 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…

It has been argued that the distinction between factivity and non-factivity is more fundamental to mental state understanding than that between false beliefs and reality. The present study examined children's growing understanding of all possible contrasts between the factive verb "know" and the non-factive verbs "think" and…

Children who are deaf or hard of hearing (DHH) show delays in Theory of Mind (ToM) development. Complement sentences such as "Eliane says that Santa Clause exists" influence ToM performance. Can a training program targeting sentential complements enhance ToM? Twenty-one French-speaking DHH children (M[subscript age] = 8 years 11 months)…

Purpose: Children with developmental language disorder (DLD) experience difficulties with an important Theory of Mind milestone, namely, false belief (FB) reasoning. Their FB success relates to mastery of a linguistic structure that is also challenging for them, namely, sentential complements (e.g., "Claire says/thinks [that Santa Claus…

First-order theory of mind (ToM) development has shown to conform to a Guttman scale, with desire reasoning developing before belief reasoning. There have been attempts to test for internal consistency and scalability in advanced ToM, but not over a broad age range and only with a limited set of tasks. This 2-year longitudinal study (N = 155;…

Mental state terms are believed to be closely related to the development of Theory of Mind (ToM). This study focuses on mental state verbs (MSVs) and investigates how they are used by Japanese-speaking mother-child dyads compared to their English-speaking counterparts. Analyses of their spontaneous speech from the CHILDES archives show that…

This study addresses the question as to what cognitive abilities influence performance on article choice and direct object scrambling in high-functioning Dutch-speaking children with Autism Spectrum Disorder (ASD). Schaeffer (2016/2018) shows that a group of 27 high-functioning Dutch-speaking children with ASD, aged 5-14, overgenerates the…

Background: According to the linguistic determinism approach, knowledge of sentential complements such as: "John says that the earth" is flat plays a crucial role in theory of mind (ToM) development by providing a means to represent explicitly people's mental attitudes and beliefs. This approach predicts that mastery of complements…

The third-person belief ascription, "Marie believes that the contract is in the cabinet," may engender two interpretations: (1) It neutrally describes what is on Marie's mind and (2) it offers indirect evidence about reality, committing the speaker to the cabinet as the most likely location. The circumstances that lead to the evidential…

This cross-sectional study investigated the use of four verbal indices of social knowledge (personal pronouns, verb conjugations, people words and mental state language) and their concurrent relations in a sample of 287 Italian-speaking children between 18 and 36 months. Results showed that the production of all indices increased with age. Mental…

Recent advancements in the field of infant false-belief reasoning have brought into question whether performance on implicit and explicit measures of false belief is driven by the same level of representational understanding. The success of infants on implicit measures has also raised doubt over the role that language development plays in the…

An experimental study investigated the effect of the type of mental verb input (i.e., input with "think", "know", and "remember") on preschoolers' theory of mind development. Preschoolers (n = 72) heard 128 mental verb utterances presented in video format across four sessions over two weeks. The training conditions differed only in the way the…

This study investigated the influence of book genre (narrative or didactic) on mothers' language use during a book sharing interaction with their 18- to 25-month-olds. Mother-child dyads were videotaped sharing both a narrative and a didactic book, adapted from two commercially available books, and matched in terms of length, quantity of text, and…