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Summary: Cognitive Development

Piaget developed one of the earliest comprehensive theories of cognitive development in children. His conser­vation experiments are classics showing that little children do not possess concepts like liquid quantity and mass but learn them around age 5-7.

Piaget described a succession of stages in cognitive development. His biggest impact was to encourage educators to focus on age-appropriate learning materials, rather than assuming small children could be accelerated into adult-level cognitive activities.

Flavell, an American researcher, studied children's development of the distinction between appearance and reality. He showed that very young children did not grasp this distinction, which is consistent with Piaget's idea that such skills must be developed over time.

Flavell also did research on metacog­nition. Children can be taught to control their mental processes in ways that improve performance. However, even around the age of six, children tend not to use these techniques without reminders from an adult.

DeLoache studied children's ability to use symbols. She found that 36-month-olds could use a small model of a room as if it was a map, to locate a toy in the larger room, or vice versa. 30-month-olds could not yet do this.

When DeLoache convinced 30-month-olds that a small model was the same as a large room, shrunken by a fancy machine, the toddlers were able to find the toy. This pinpointed what they were lacking: the ability to relate two different spaces in an abstract way.

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