Precursors to infants' perception of the causality of a simple event

Three habituation experiments examined the perception of causal and non-causal events by infants at 6 1/4, 5 1/2, and 4 months of age. Experiment 1 replicated previous studies showing that by 6 1/4 months, infants begin to respond to the interaction of simple objects in Michottian type launching events on the basis of causality, in Experiments 2 and 3, however, younger infants exposed to the identical event sequences responded on the basis of simpler perceptual features of the launching events, and not on the basis of causality. 4-month-old infants responded to continuous versus noncontinuous movement. 5 1/2-month-old infants also responded somewhat on the basis of continuous movement. However, in addition they responded on the basis of the spatial and temporal perceptual features of the events. This change in the pattern of results over age suggests a multi-step developmental progression.