The boundaries of overimitation in preschool children: Effects of target and tool use on imitation of irrelevant actions

- Types of actions children tend to overimitate have not been systematically examined.
- The effects of types of irrelevant actions on overimitation are directly compared.
- The combination of tool use and the target of irrelevant actions affected overimitation.

Overimitation is defined as the imitation of a series of actions, including causally irrelevant ones. Although previous studies have indicated that children's overimitation tends to be flexible, there is no research directly comparing overimitation occurrences due to types of irrelevant actions such as the target of irrelevant action or tool use. To identify the boundary of overimitation-that is, the point at which it occurs or not-Study 1 focused on the target of causally irrelevant tool-using actions. Specifically, the study examined the demonstration of irrelevant actions toward a main apparatus, a disconnected apparatus, or an actor's own body, followed by the demonstration of causally relevant actions, to 2-, 3-, and 5-year-old children (N = 59). Results indicated that children overimitated actions toward the apparatuses more than they did the actions toward an actor's body. These results showed that overimitation was affected by the target, the apparatus, or the actor's own body. Study 2 investigated the effect of tool use toward the disconnected apparatus or an actor's body based on the findings in Study 1. Concretely, Study 2 added two actions without tool use (e.g., action toward an actor's own body without tool use and action toward an apparatus without tool use) to Study 1's actions for comparison. The results of this study showed that children overimitated the action toward the apparatus and the action with the tool more than the action toward an actor's own body and the action without the tool. Taken together, these findings suggest that two factors are involved in the occurrence of overimitation: the target of the action (i.e., the apparatus) and the use of a tool. The current findings provide suggestions for considering important aspects of overimitation that are worthy of more attention.