"Developmental changes in imitation were examined in three experiments with 6- to 24-month-old infants. In all experiments, infants in the demonstration condition observed an experimenter perform three specific actions with a puppet. Their ability to reproduce those actions was assessed for the first time during the test in the absence of prior practice. Infants in the control condition received equivalent exposure to the puppet and the experimenter but were not shown the target actions. The results of Experiment 1 showed that 12-, 18-, and 24-month-old infants exhibited clear evidence of imitation following a 24-hour delay (deferred imitation). In addition, the findings of Experiment 1 demonstrated that the 18- and 24-month-old infants reproduced more of the target actions during the test than the 12-month-olds. The results of Experiment 2 showed that 6-month-olds performed as well as 12-month-olds when they were tested in the absence of a delay (immediate imitation). Finally, the results of Experiment 3 showed that, with additional exposure to the target actions, even 6-month-old infants exhibited deferred imitation following a 24-hour delay. Taken together, these findings have important implications for current theories of the development of imitation and memory during the first 2 years of life."