For years, I wondered how babies learn to associate the percept of seeing somebody do something with the percept of doing it themselves, when the two share nothing to begin with. In other words, how do babies learn to imitate? My sense now, after some observation, is that young babies do not learn by imitation. Instead, they try movements and sounds by trial and error, and learn by reinforcement: by associating their own actions with satisfaction or pain, whether self-inflicted or caused by others. In this regard, my prediction is that mirror neurons (neurons which are activated both when an animal executes an action and when it observes the same action performed by somebody else) appear rather late in development, after the context or meaning of each is understood, so that they can be associated.

It's only once babies have learned the equivalence relationships between their actions and others' that imitation becomes an important way to learn.

Altadena, 1/15/2007