Young children's understanding of belief constraints on intention

One important characteristic of rational action is that our intentions should be consistent with our beliefs. That is, an intention to perform an action should normally be accompanied by a belief that the action will in fact be performed, and be supported by other relevant beliefs. Thus, if the intention is unfulfilled it will have been accompanied by false beliefs. Two studies examined whether 3-year-olds understand these belief constraints on intention. Children were shown films in which actors displayed great surprise and sadness at their failure to bring about the outcomes they intended and expected. They were then questioned about the actors' unfulfilled intentions and false beliefs. In both studies their understanding of unfulfilled intentions was excellent, and significantly better than their understanding of false beliefs. Nevertheless, they also revealed considerable understanding of the beliefs underpinning intentions and, in Study 2, their performance in terms of such beliefs was significantly better than that on standard false-belief tasks. Three-year-olds thus appear to have a threshold understanding of the role of belief in intentional action.