Young infants' sensitivity to movement information specifying social causality

Adults and 3- to 6-month-old infants were tested for their visual preference for two different dynamic displays presented simultaneously on two side-by-side computer monitors. Each display consisted of a pair of colored discs moving either independently (the independent display) or in systematic interaction (the "chase" display), never actually contacting one another. Except for the relative spatio-temporal dependence of the discs' movements, all dynamic parameters on the two displays were controlled and maintained equal. Analysis of looking behavior showed that adults as well as infants looked differentially at the displays. Patterns of preference depended on age. For the infants who completed the experiment, there was a significant transition from more looking at the chase to more looking at the independent display as a function of age. Adults as well as the older, attentive infants, showed enhanced visual attention to the independent display. These results provide first evidence of young infants' sensitivity to movement information specifying social causality for adult observers.