Counterfactual and mental state reasoning in children with autism.

The contributions of counterfactual conditional reasoning (CCR), belief understanding, and inferential reasoning to the performance of children with autism (CWA) on standard false belief tasks were investigated. To assess the roles of these three factors, we compared the performance of CWA on physical-state CCR tasks (which do not require either an understanding of belief or inferential reasoning); on Wellman and Bartsch's (1988) nonstandard tests of false belief (which require an understanding of belief, but not CCR or inferential reasoning), and on standard tests of false belief tasks. The CWA were impaired relative to controls on the physical-state CCR and standard false-belief tasks, but not on the nonstandard false-belief tasks, and the CWA's performance on the physical-state CCR and standard false-belief tasks correlated highly, even when the effects of verbal ability were partialled out. Finally, the CWA's performance on standard false-belief tasks was more impaired than their performance on the physical-state CCR tasks. We concluded that impaired performance on standard false-belief tasks in autism is associated with defective competence in CCR (or some of its component skills), plus defective competence in inferential reasoning and possibly generativity, but that impaired performance is not caused by an inadequate understanding of belief. The results are discussed in relation to other hypotheses concerning the cause or causes of impaired performance on standard false-belief tasks in children with autism.