The relation between children's lie-telling and their social and cognitive development was examined. Children (3-8 years) were told not to peek at a toy. Most children peeked and later lied about peeking. Children's subsequent verbal statements were not always consistent with their initial denial and leaked critical information revealing their…

Two experiments tested two, three, and four year olds' ability to understand false beliefs. Results of both experiments support earlier claims that an understanding of false beliefs and deceptive ploys emerges at around age four. Two and three year olds can be led to produce such ploys but show no clear understanding of their effect. (GLR)