How 7-month-olds interpret ambiguous motion events: category-based reasoning in infancy.

This paper investigates the role of static and dynamic attributes for the animate-inanimate distinction in category-based reasoning of 7-month-olds. Three experiments tested infants' responses to movement events involving an unfamiliar animal and a ball. When either the animal or the ball showed self-initiated irregular movements (Experiment 1), infants expected the previously active object to start moving again. When both objects were moving together in an ambiguous motion event (Experiment 2), infants expected only the animal to start moving again. Initial looking preferences for each object did not influence results. When either the facial features of the animal were removed, or its furry body was replaced by a plastic spiral in an ambiguous motion event (Experiment 3), infants formed no clear expectation regarding future movements. Based on this set of findings we conclude that 7-month-olds flexibly combine information about the static and dynamic properties of objects in order to reason about motion events.