The development of counterfactual reasoning about doubly-determined events

Previous studies of children's counterfactual reasoning have focused on scenarios in which a single causal event yielded an outcome. However, there are also cases in which an outcome would have occurred even in the absence of its actual cause, because of the presence of a further potential cause. In this study, 128 to 152 children aged 4-9 years reasoned counterfactually about such scenarios, in which there were 'doubly-determined' outcomes. The task involved dropping two metal discs down separate runways, each of which was sufficient to knock over a toy pig. One of the runways was shorter than the other, meaning that one of the discs actually knocked over the pig whereas the other always arrived too late to do so. Children were asked whether the pig would have been knocked over in the absence of the first metal disc descending the runway. We found that children could accurately answer such counterfactual questions by 6-7 years.