The Contribution of Grammar, Vocabulary and Theory of Mind in Pragmatic Language Competence in Children with Autistic Spectrum Disorders

Purpose: Children with autism spectrum disorders (ASDs) and children with developmental language disorder (DLD) face challenges with pragmatics, but the nature and sources of these difficulties are not fully understood yet. The purpose of this study was to compare the competence of children with ASD and children with DLD in two pragmatics tasks that place different demands on theory of mind (ToM) and structural language.Method: Twenty Spanish-speaking children with ASD, 20 with DLD, and 40 age- and language-matched children with neurotypical development were assessed using two pragmatics tasks: a linguistic pragmatics task, which requires competence with structural language, and a social pragmatics task, which requires competence with ToM as well.Results: For linguistic pragmatics, the ASD group performed similarly to the DLD and language-matched groups, and performance was predicted by structural language. For social pragmatics, the ASD group performed lower than the DLD and language-matched groups, and performance was predicted both by structural language and ToM.Conclusions: Children with ASD and children with DLD face difficulties in linguistic pragmatics tasks, in keeping with their structural language. Children with ASD face exceptional difficulties with social pragmatics tasks, due to their difficulties with ToM. The distinction between linguistic and social pragmatic competences can inform assessment and intervention for pragmatic difficulties in different populations.

Specific language impairment (SLI) has traditionally been characterized as a deficit of structural language (specifically grammar), with relative strengths in pragmatics. In this study, comprehensive assessment of production, comprehension, and metalinguistic judgment of referring expressions revealed that children with SLI have weaknesses in both structural and pragmatic language skills relative to age-matched peers. Correlational analyses highlight a relationship between their performance on the experimental tasks and their structural language ability. Despite their poor performance on the production and comprehension tasks, children with SLI were able to recognize pragmatically under-informative reference relative to other types of utterance, although they imposed a less severe penalty on such expressions than typically developing peers, a pattern that supports the pragmatic tolerance account. Our novel methodology (which probed structural abilities from both the speaker's and hearer's perspectives as well as metalinguistic and pragmatic skills in the same sample) challenges the assumption that pragmatic errors stem from deficits in social cognition and instead supports recent findings suggesting that when the impact of structural language is isolated, pragmatic deficits may be resolved.