A Similarity Heuristic in Children's Possibility Judgments

Children often judge that strange and improbable events are impossible, but the mechanisms behind their reasoning remain unclear. This article (N = 250) provides evidence that young children use a similarity heuristic that compares potential events to similar known events to determine whether events are possible. Experiment 1 shows that 5- to 6-year-olds who hear about improbable events go on to judge that similar improbable events can happen. Experiment 2 shows that 5- to 6-year-olds more often affirm that improbable events can happen if told about related improbable events than if told about unrelated ones. Finally, Experiment 3 shows that 5- to 6-year-olds affirm the possibility of improbable events related to known events, but deny that related impossible events can happen.