Front Cover; Mental Retardation: Some Recent Developments in the Study of Causes and Social Effects of this Problem; Copyright Page; Table of Contents; Foreword; Preface; Chapter 1. Mental Retardation; No Immediate Danger of Decline of National Intelligence; The Need for Information; Prevalence of Mental Retardation; Causes of Mental Retardation; Chemical Disorders; Possibilities of Treatment; Other Enzyme Defects; Recessive Heredity; Children of the Mentally Retarded; Mendelian Inheritance; Consanguinity; Detection of Carriers; Significance of Carrier State; Direct Transmission; Mutations

A Hereditary Deformity of Head and HandsParental Age; Chromosome Studies; Abnormalities of Sex Chromosomes; The Barr Body; Turner's Syndrome; Down's Syndrome; Human Mosaics; Malformation of the Nervous System; Hydrocephalus, Spina Bifida and Anencephaly; Blood Groups and Mental Retardation; Cerebral Palsy and Mental Retardation; Twins; Birth Hazards; Potential and Achievement; Research in Rehabilitation; Cultural Retardation; The Brooklands Experiment; The Need for Further Effort; Further Reading