Development of Pragmatic Language Understanding in Children with Autism Spectrum Disorder
Objectives: We examined how the performance of children with ASD and typically developing (TD) children changed across ages and explored which conversational rules (i.e., Gricean maxims) children with ASD had difficulty understanding by using the Japanese version of Conversation Violation Test (CVT-J).
Methods: Participants were 13 children with ASD (mean age: 6 years 10 months; range: 5 years 2 months to 9 years 7 months) and 13 TD children (mean age: 6 years 9 months; range: 5 years 1 month to 9 years 5 months), individually matched on chronological age and sex and group-matched on IQ. The CVT-J consisted of the following five types of questions based on Gricean maxims: Relation (be relevant to the topic), Quality (be truthful and avoid saying something lacking adequate evidence), Quantity I and II (avoid less (I) or more (II) information than is required for the current purposes of the conversation), and Politeness (be polite). Each maxim had five questions, and the total number of questions was 25. Children watched a scenario that featured three hand-puppets engage in question-exchange communication: one puppet was a questioner and the other two were responders. One responder gave a correct answer and the other gave an answer that violated one of the Gricean maxims. The experimenter asked children to select the puppet that gave the wrong answers.
Results: Overall, TD children performed better on the CVT-J than children with ASD (mean score: ASD 17.5; TD 21.4, p < .05). In order to determine which conversational rules children with ASD have difficulty understanding, we compared the performance of the ASD group with that of the TD group in each conversational rule. We found that TD children performed better than children with ASD in the maxims Quality and Quantity I (ps < .05). Change of the performance across ages (difference in slope) did not significantly differ between the groups. At a certain age (ASD: around 8 years, TD: around 6 years), both groups passed 80% correct.
Conclusions: Two important findings were obtained. First, TD children performed better than children with ASD on certain conversational rules. Second, children with ASD understood this task well (80% correct) by around eight years old, although the performance of the ASD group followed that of the TD group across ages. We discuss whether children with ASD have specific difficulty understanding some conversational rules and the ways that children with ASD can more easily understand conversational rules.