Children's representation of coincidence

People relish thinking about coincidences-we puzzle over their meanings and delight in conveying our experiences of them to others. But whereas some research has begun to explore how coincidences are represented by adults, little is known about the early development of these representations. Here we explored factors influencing coincidence representations in both adults and children. Across two experiments, participants read stories describing co-occurring events and then judged whether these constituted coincidences. In Experiment 1 we found that adults' coincidence judgments were highly sensitive to the presence or absence of plausible explanations: as expected, adults were more likely to judge co-occurrences as a coincidence when no explanation was available. Importantly, their coincidence judgments were also modulated by the number of events that co-occurred. Adults tended to reject scenarios involving too many co-occurring events as coincidences regardless of whether an explanation was present, suggesting that observing suspiciously many co-occurrences triggered them to infer their own underlying explanation (and thus blocking the events' interpretation as a coincidence). In Experiment 2 we found that 4- to 10-year-old children also represent coincidences, and identify them via the absence of plausible explanations. Older children, like adults, rejected suspiciously large numbers of co-occurring events as coincidental, whereas younger children did not exhibit this sensitivity. Overall, these results suggest that representation of coincidence is available from early in life, but undergoes developmental change during the early school-age years.