Automatic Imitation in Children: Age-Related Change and Comparison to Adults

Automatic imitation, in which one person's movement is affected by the observation of another person's movements, has been widely reported. However, it remains unclear how automatic imitation changes over a wide age range, particularly during childhood. In this study, we examined the differences in the tendency for automatic imitation between adults and children and the cross-sectional age-related changes in children aged 5-12 years, using a stimulus-response conflict paradigm. In this task, participants perform a choice-reactive finger movement corresponding to a given response stimulus while observing another participant's compatible or incompatible movement stimuli. The tendency for automatic imitation was assessed based on the reaction time, correct rate, and inverse efficiency score. The results showed that the degree of automatic imitation was weak until the children were 7 years old. Interestingly, our results show that the tendency for automatic imitation during childhood changed to an inverted U-shape, indicating nonlinear changes in automatic imitation during childhood.