Early understanding of perception as a source of knowledge.

Two studies investigated preschool children's ability to infer another person's knowledge or ignorance on the basis of that person's recent perceptual experience. In Experiment 1 children were questioned about their own and a puppet's knowledge of a hidden object's color and about their own and the puppet's ability to see the hidden object. Three- and 4-year-olds attributed knowledge and perceptual experience to the person (either themselves or the puppet) who had viewed the hidden object, but not to the person who did not view it. Experiment 2 further investigated 3-year-olds understanding of perception as a source of knowledge. Children were asked to indicate which of two puppets, one who had viewed a hidden object and one who had not, would be able to tell them the object's color. Children chose the correct puppet more often than would be predicted by chance. The results of these experiments suggest that understanding of perception as a source of knowledge is present by the age of 3 years.