Understanding Mental Retardation constitutes a guide to research and theory for specialists and students alike. Throughout, Edward Zigler and Robert M. Hodapp draw on our knowledge of normal development to inform their discussion of various aspects of retardation. Two introductory chapters provide the developmental framework for this discussion. Topics addressed include issues of definition, classification, and prevalence; motivation and personality factors; intervention in the lives of organically and so-called familial retarded persons; the possibility of 'miracle cures'; and the problems of institutionalization and mainstreaming. The authors' clear presentation and judicious evaluation of the available evidence will attract the attention of a wide audience.