Why do children overimitate? Normativity is crucial.

Recent research has documented that children readily engage in overimitation, that is, the reproduction of causally irrelevant elements within a bigger action sequence. Different explanations have been put forward. Affiliation accounts claim that children overimitate to affiliate with the model. Causal confusion accounts claim that children mistakenly perceive causally irrelevant elements as causally relevant and, thus, imitate them. Normativity accounts claim that overimitation arises when children view causally irrelevant elements as an essential part of an overarching conventional activity. To test among these accounts, we had children watch a model produce some effect by performing a sequence of causally irrelevant and relevant acts, with the latter resulting in some effect. In two conditions, the model presented the action sequence as focused either more on the method or more on the goal, with the normativity account predicting that children should interpret the causally irrelevant element as essential more often in the method condition than in the goal condition. Three measures were used: (a) children's own overimitation, (b) their spontaneous responses to a puppet engaging in or refraining from overimitation, and (c) their explicit judgments about the puppet's behavior. Results revealed that overimitation was frequent in both conditions. In addition, however, children protested against the puppet only when she did not overimitate, they did so more in the method condition than in the goal condition, and they explicitly judged omission of the irrelevant actions to be a mistake in the method condition. These results are not readily compatible with affiliation and causal confusion accounts, and they speak in favor of normativity accounts.