Are children with autism deaf to Gricean maxims?

High-functioning children with autism show a severe deficit in the development of pragmatics whereas their knowledge of syntax and morphology is relatively intact. In this study we investigated further their selective communication impairment by comparing them with children with specific language impairment (SLI) and normally developing children. We used a pragmatic task that involved the detection of utterances that violate conversational maxims (avoid redundancy, be informative, truthful, relevant, and polite). Most children with autism performed at chance on this task, whereas all children with SLI and all normal controls performed above chance. In addition, the success of children with autism on the pragmatics task was related to their ability to attribute false beliefs. These results are consistent with the idea that communication deficits in autism result from a selective impairment in representing propositional attitudes. Their implications for domain-specific views of cognitive development are discussed.