'If pigs could fly': A test of counterfactual reasoning and pretence in children with autism

The authors report an experiment with children with autism, using the Dias & Harris (1990) method, to test the predictions that: (i) children with autism will show intact count counterfactual reasoning, and (ii) since such children are impaired in pretence, they would not then show the normal facilitation effect of pretence on counterfactual reasoning ability. Children with autism and matched verbal mental age (VMA) controls were presented with a series of counterfactual syllogisms, in two conditions. One condition (Counterfactual plus Pretence) involved prompting the child's imagination during the reasoning task, whereas the other condition (Counterfactual Only) included no such prompting. Results showed chat both normal 4-5-year-old children, and children with moderate learning difficulties improved in their reasoning performance when prompted to use imagination. This replicates and extends findings from Dias & Harris (1990). In children with autism, however, performance was good in the Counterfactual Only condition, but became worse when imagination was prompted. These results show that although abstract counterfactual reasoning appears intact in children with autism, their counterfactual reasoning is not facilitated by pretence in the normal way.