Children's understanding of preexisting differences in knowledge and belief

A basic developmental task fur children is to understand how people may differ in what they know and believe. Some such differences stem from situationally provided contrasts in immediate information; others reflect more pervasive, naturally occurring variations in thoughts and beliefs. This article reviews research relevant to children's understanding of the second form of cognitive difference. The paradigms reviewed include false belief, origins of knowledge, ambiguity, explicit judgments of knowledge, communication, and information seeking; the target contrasts include self vs other, younger vs older, and familiar vs unfamiliar. This article identifies developmental changes for each of the forms of understanding, with impressive early competence in some instances and surprisingly protracted development in others. It is argued that a consideration of preexisting differences in belief provides an important complement to the situational emphases that have characterized theory-of-mind research, extending both the range of beliefs examined and the scope of developmental changes identified. (C) 2000 Academic Press.