Adults and 3- to 6-month-old infants were tested for their visual pref
erence for two different dynamic displays presented simultaneously on
two side-by-side computer monitors. Each display consisted of a pair o
f colored discs moving either independently (the independent display)
or in systematic interaction (the ''chase'' display), never actually c
ontacting one another. Except for the relative spatio-temporal depende
nce of the discs' movements, all dynamic parameters on the two display
s were controlled and maintained equal. Analysis of looking behavior s
howed that adults as well as infants looked differentially at the disp
lays. Patterns of preference depended on age. For the infants who comp
leted the experiment, there was a significant transition from more loo
king at the chase to more looking at the independent display as a func
tion of age. Adults as well as the older, attentive infants, showed en
hanced visual attention to the independent display. These results prov
ide first evidence of young infants' sensitivity to movement informati
on specifying social causality for adult observers.