Forgetting and symbolic insight: Delay improves children's use of a novel symbol.

To use a symbol, children must understand that the symbol stands for something in the world. This development has often been investigated in the model-room task in which children use a scale model to try to find a toy that is hidden in the room that the model represents. To succeed, children must acquire dual representation; they must put aside their understanding of the model as an object and focus more on what the model represents. Here we suggested that forgetting irrelevant details or misleading information may be an important part of acquiring and maintaining dual representation. Based on prior research showing that forgetting can promote insight in children and adults and that a small sample of 3-year-olds could improve on the model-room task with a delay, we hypothesized that taking a break during the model-room task would facilitate forgetting and hence symbolic insight. A total of 88 3-year-olds performed 8 trials of the model-room task. Half of the children received a 24-h delay after Trial 4, and half performed the 8 trials consecutively. Children who received a 24-h delay had better symbolic performance on the last 4 trials compared with children whose testing sessions occurred consecutively on 1 day, even when statistically controlling for the effects of learning over trials and memory on children's performance. This study provides strong initial evidence that a delay can promote symbolic insight in 3-year-old children.