The Development of Cognitive Judgment in the Mentally Retarded: A Selective Review of Piagetian-Inspired Research

Abstract

Five categories of cognitive judgments were discussed, relative to Piagetian levels of development, as follows: time, weight conservation, Type I illusions (Poggendorf), moral judgment, and color discrimination. Normative research and the mentally retarded in five areas of these judgments was reviewed, with additional suggestions for research being offered.