We are requesting 5-year renewal of support for a research center on mental retardation and related aspects of human development. The integrated research attack on the social problems of mental retardation is interdisciplinary within the behavioral/social sciences, is characterized as behavioral, developmental, social, and educational, and is organized around the conceptual area of social ecology. The goal is to produce information that will be useful in increasing the social integration and decreasing the social vulnerability of mentally retarded persons. The program includes research on personal characteristics of mentally retarded and nonretarded individuals, but increasingly incorporates dimensions as variables of classification. Learning and social adaptation will be studied in a variety of settings, as will the characteristics of those settings and person-setting matches with respects to the accomplishment of specific developmental tasks. We propose to study environmental characteristics that can be changed in order to enhance social integration and decrease social vulnerability. The Kennedy Center is organized into four active component research institutes, arranged a long a continuum of research focus from molecular and person oriented to exosystem oriented, with intermediate research focused upon mesosystems and macrosystems. We propose to renew the research efforts of these institutes, to continue to do research on basic learning mechanisms in mental retardation, to focus research attention upon family variables, to devise and evaluate educational strategies to enhance the development of mentally retarded children, to gain knowledge of settings in which mentally retarded persons function, and to undertake systematic evaluation of developmental intervention programs.