Infants predict other people´s action goals

When and how do infants come to understand other people's actions? Understanding others is crucial for social development because it allows the young child to coordinate its own actions with those of others, learn new actions from them, and understand their motives and intentions.

Evidence from neuroscience suggest that the understanding of other people's actions is accomplished by a mirror neuron system that maps the observed actions onto the observer's motor systems, that is, other people's actions are understood in terms of one's own actions. In line with this, adults fixate the goal of an observed action ahead of time in the same way as they fixate the goals of actions performed by themselves.

Do infants also understand the actions of others in this fashion? We found solid evidence for such competences in 12-month-old infants. When they observed a person moving an object between two positions, they moved their gaze to the goal position before the hand arrived there with the object. Six-month-olds, who cannot perform this kind of tasks, did not move their gaze to the goal ahead of time under these conditions.

Instead, they tracked the action with their eyes and arrived at the goal after the action had been completed, indicating poor understanding of the observed action. Furthermore, when presented with objects that moved by themselves, neither 12-months-olds nor adults predicted the goal of the movements.

Our study supports the hypothesis that infants understand other people's actions by a mirror system that maps the observed actions onto their own action system. Furthermore, it shows that such understanding develops during the second half of the first year of life. These findings have dramatic implications for how we conceptualize the development of social communication and competences, like imitation, language and empathy.