This paper presents information on isolated children and describes a study being undertaken to examine the role of isolation in reported cases of child abuse and neglect. The effects of extreme isolation on language and psychological development are emphasized. The importance of early socialization is seen in relation to normal development. Ancient and medieval studies in which children were isolated to discover an instinctive language are described in the text and appendix. Reports of two modern children who were isolated from birth are also presented. In the study described in this paper, 51 cases of child abuse and neglect recently reported in the United Kingdom were examined. In the cases selected for review, isolation was not cited as a major factor, so that its role as a contributing factor in child abuse could be assessed. Results indicate that, although isolation was not seen as worthy of inclusion in legal charges, it appears to be a significant factor in all stages of case histories. The case of a neglected boy is reconstructed, and developmental damage produced by isolation is discussed. (SB)