Rapid change in the symbolic functioning of very young children.

A remarkable difference in the understanding of the symbolic relation between a scale model and the larger space that it represented was displayed by two age groups of young children. Three-year-old children who observed an object being hidden in a model knew where to find an analogous object hidden in the corresponding location in a room, but 2.5-year-old children did not. The success of the group of older children reveals an advance in their cognitive flexibility: they think of a model in two ways at the same time--both as the thing itself and as a symbol for something else.