Thinking outside the Box: Causal uncertainty motivates children's over-imitation.

Children are high fidelity imitators, copying perceivably unnecessary actions in many circumstances, although the reason for this 'over-imitation' is debated. The Dual-Process Model (Schleihauf & Hoehl, 2020) proposes that children default to 'blanket copy' others when unprompted to consider an alternative strategy. In this pre-registered study, we test the Dual-Process Model and an alternative possibility: that children use over-imitation in the face of uncertainty to test their causal predictions. 60 5-to-8-year old children completed a classic over-imitation paradigm where they watched a demonstrator retrieve a toy from a container using necessary and unnecessary actions. They were then instructed to retrieve the toy themselves and their inclusion of the unnecessary actions was coded. Half of the children completed a causal discrimination task prior to the over-imitation task, and half completed it subsequently. Contrary to the predictions of the Dual-Process Model, there was no difference in the amount of over-imitation displayed by children in the imitation-first and the discrimination-first conditions. Instead, children acted in accordance with their causal understanding. Over-imitation was most prevalent when children were uncertain about the causality of unnecessary actions. Amongst over-imitators, causal discrimination was improved if children reported their understanding after over-imitating. This study supports the idea that children actively use over-imitation as a strategy to learn about objects in the world.