Abstract
When newly born into this world, there is an overwhelming multitude of things to learn, ranging from learning to speak to learning how to solve a mathematical equation. Amidst this abundance, action perception is developing already in the first months of life. Why would learning about others' actions be among the first items to acquire? What is the relevance of action perception for young infants? Part of the answer probably lies in the strong dependence on others. Newborn human infants need caretakers even for fulfilling their basic needs. Weak neck muscles make it hard for them to lift up their head, and most of their movements come across as uncoordinated. Clearly, getting themselves a drink or dressing themselves is not part of their repertoire. Their reliance on their caregivers makes these caregivers and their actions important for the young infant. Seeing that the caregiver responds to their calls can already reduce some of the stress that comes with being so dependent. As such, it is helpful for an infant to learn to distinguish different actions of the caregiver. Not only are the caregivers' actions focused on the infant's physical needs, but also on helping the infant to regulate her emotions. Parents typically comfort a baby by softly rocking them, and by talking and smiling to them. Social interaction between caregiver and infant thus starts immediately after birth, and these interactions help them to bond. In the context of social interaction, it is useful to be able to distinguish a smile from a frown. Interpreting the facial actions of others is vital to successful communication. Moreover, in the period in which infants are still very limited in their own actions, observing others' actions forms a main resource for learning about the world. Making sense of others' actions is therefore of central importance already during early development.
