Why don’t they just let it go?

Discrepancies between what children expect about physical causality (indexed by looking time) and how they act on that knowledge have led to criticisms of claims about what infants “know.” Baillargeon [Baillargeon, R. (1999). Young infants’ expectations about hidden objects: A reply to three challenges. Developmental Science, 2, 115–163] advocates examining more tasks before revising views of early cognitive development. We report another discrepancy which suggests an additional indicator of what is salient for preverbal infants. While examining the Užgiris–Hunt test performances of 40 children (26 females), 7.6–26.9-months-old, infants appeared captivated by the bouncing of a small rubber ball. However, most infants reproduced the motion of the bounce event itself, repeatedly hitting the ball against the table, rather than the experimenter's action (dropping). Comparing performances of those who did and did not imitate the drop, two possibly interrelated interpretations remained consistent with the data: infants perform goal-directed imitation of interesting phenomena, perhaps because they believe they must apply force to make them happen.