Do I get what you get? Learning about the effects of self-performed and observed actions in infancy.

The present study investigated whether infants learn the effects of other persons' actions like they do for their own actions, and whether infants transfer observed action-effect relations to their own actions. Nine-, 12-, 15- and 18-month-olds explored an object that allowed two actions, and that produced a certain salient effect after each action. In a self-exploration group, infants explored the object directly, whereas in two observation groups, infants first watched an adult model acting on the object and obtaining a certain effect with each action before exploring the objects by themselves. In one observation group, the infants' actions were followed by the same effects as the model's actions, but in the other group, the action-effect mapping for the infant was reversed to that of the model. The results showed that the observation of the model had an impact on the infants' exploration behavior from 12 months, but not earlier, and that the specific relations between observed actions and effects were acquired by 15 months. Thus, around their first birthday infants learn the effects of other persons' actions by observation, and they transfer the observed action-effect relations to their own actions in the second year of life.