Proceedings of the Annual Meeting of the Cognitive Science Society

Many event descriptions are true only when the event comes to its natural end point: e.g., a “feeding” event culmi-nates when the feed-ee has eaten, not simply when food is provided. Do non-linguistic event conceptualizations reflect attentionto natural culmination points? We tested adults and 14-month-olds to ask: provided two events with the same ACTION butdifferent ENDPOINTs - one a naturally expected result, the other only partially achieved - do adults and infants perceive themas members of the same event category or of different categories? Adults were asked to rate the similarity between the twoevents; infants were habituated to one event and tested for dishabituation when it was switched to the other. Adult data suggestthe difference between a complete and a partially-complete event is registered, and carries more psychological weight than amere perceptual difference. Infant data (ongoing) will show the developmental origin of such conceptualizations.