Imitation in infancy: the development of mimicry.

Parents of 162 infants ages 6 to 20 months modeled subsets of four of the same set of eight behaviors, each for a maximum of 3 min, and encouraged their infants to imitate. Proportions of infants producing each behavior (a) when it was modeled and (b) during modeling of a different behavior were compared to estimate the age at which infants mimicked each kind of behavior. No reproduction of these motor acts--that is, no mimicry--was observed at 6 months. Mimicry appeared to develop slowly through most of the 2nd year, emerging at different ages for different behaviors. The findings suggest that newborns' behavioral matching may not be continuous with mimicry later in infancy. Imitation is probably not one behavioral competency with one underlying mechanism. It is more likely a category of different ways of combining and using different types of knowledge, some of which develop across the first 2 years of life.