Imitation was tested both immediately and after a 24-hr retention interval in 6-week-old infants. The results showed immediate imitation, which replicates past research, and also imitation from memory, which is new. The latter finding implicates recall memory and establishes that 6-week-olds can generate actions on the basis of stored representations. The motor organization involved in imitation was investigated through a microanalysis of the matching response. Results revealed that infants gradually modified their behavior towards more accurate matches over successive trials. It is proposed that early imitation serves a social identity function. Infants are motivated to imitate after a 24-hr delay as a means of clarifying whether the person they see before them is the same one they previously encountered. They use the reenactment of a person's behavior to probe whether this is the same person. In the domain of inanimate objects, infants use physical manipulations (e.g., shaking) to perform this function. Imitation is to understanding people as physical manipulation is to understanding things. Motor imitation, the behavioral reenactment of things people do, is a primitive means of understanding and communicating with people.
Keywords: communication; cross-modal; development; faces; identity; imitation; memory; mental representation; motor coordination; self; theory of mind.