We explore whether people’s judgments about the possibility of events are predicted by their knowledge of similar events. Participants read 80 events from a list including events that were ordinary, unusual, and impossible. Participants rated whether the events were possible or whether the events were similar to events they knew to have happened. The averaged ratings for each judgment were strongly correlated, and the correlation remained significant in an analysis limited to a subset of the events that were neither viewed as totally impossible, or as extremely similar to known events. These findings provide preliminary evidence that adults may judge whether events are possible by relying on a memory-based heuristic which aims to identify whether these events are similar to known events.

Children often judge that strange and improbable events are impossible, whereas adults usually accept the possibility of such events. This shows that children’s reasoning about possibility is immature, but it remains unclear how children reason about the possibility of improbable events. We explore whether children use a novel event’s similarity to a known event to infer whether the event can happen. We told 4- to 6- year-olds (N=120) either ordinary or improbable facts and then asked if a related improbable event was also possible. The facts contained no causal information that could be extended to the occurrence of a similar event. Children who heard improbable facts more often agreed that similar improbable events were possible than children who heard ordinary facts. This suggests that the mere knowledge that an event can happen influences children’s beliefs about the possibility of other unfamiliar-but- similar events.

The ability to anticipate the future improves markedly acrossthe preschool years. One major area of improvement is in chil-dren’s ability to consider their future preferences. Whereas5-year-olds understand they will prefer adult items in the fu-ture, 3-year-olds indicate they will continue to prefer childitems. In the present research, we show that preschoolers(N=120) show an ownership-advantage in their future-orientedthinking—they are better able to indicate which objects theywill own as adults than to indicate what they will like. Thesefindings are informative about the basis for children’s difficultyanticipating their future preferences, and also reveal differ-ences between how children think about ownership and prefer-ences.