In general, cognitive development continues at a rapid pace during the preschool years. Improved language skills and the ability to count, play games, and even begin to read and write all reflect advances in the preschool child's cognition. The development of symbolic thought is of particular importance.

While the toddler learns to symbolize objects and events that are not present, the preschool child learns to manipulate objects and events in his or her own mind. In other words, the preschool child is capable of imagination. Not only can preschool children refer to something that is not present, they can change it in their mind. This significant shift opens the door to pretend play, to fantasy, and even to lying.

In keeping with the new capacity for fantasy, children this age are very drawn to pretend play. They love to play dress-up, to pretend to be parents, to play house, or to imitate adult roles that they see in their life, such as a teacher, fireman, or doctor.

While some pretend play is evident in the toddler years, it is much more elaborated in the preschool years. A toddler may pretend to talk on the phone or dress up in Mommy's shoes, but a preschool child enacts whole stories, with different children assigned different roles in the drama.