Nine-Month-Old Infants’ Understanding of Actions: What’s Priming Got to Do With It?

Is it necessary for infants to perceive a fully specified human form in order to simulate a goal-directed action? Three experiments tested for simulation using an observation version of the A-not- B paradigm, where simulation of the experimenter’s reaches results in infants committing a perseverative error. Here, unlike previous studies, only the experimenter’s hands were visible, without any verbal input (Experiment 1), with verbal input (Experiment 2), and after infants’ were primed with a representation of the experimenter’s full body before hiding all but his hands behind a curtain (Experiment 3). The results revealed that infants only simulate the experimenter's reach following priming in Experiment 3. This suggests that infants differentiate disembodied from fully specified hands, do not simulate disembodied hands unless the representation is linked with a fully specified body, and that recent experience modifies infants’ understanding of goal-directed agents.