Human infants' perception and understanding of others' actions

The perception and understanding of others' actions is foundational to how we communicate and learn about the social and physical world. During the past 25 years a good deal of research has focused on how the links between the observation and execution of actions could underly infants' understanding and prediction of others' behaviors. In this article, we critically review the empirical evidence suggesting that the development of action understanding is related to motor experience. This research is focused on infants' perceptions and predictions of others' goals, but actions involve more than goals which is why infants' coding of the movements of an action are also reviewed. One critical issue that remains unresolved in the literature is whether the processes responsible for mapping the observation and execution of actions are limited to human actions or whether they generalize to non-human actions as well. Although much of the evidence suggests a difference, we identify methodological problems and alternative interpretations that have not been fully addressed. One reason for these problems is that action understanding has been studied largely through the lens of motor development. In the last section, we suggest that this field of inquiry has become somewhat stagnant and needs to adapt a developmental systems perspective: Action understanding should be studied as a dynamical system in which its development changes as a function of not only motor experience, but also as part of a larger system of developing behaviors that interact in complex and nonlinear ways.