This research project is a continuation of broad--gauged investigations of the relationship between cognitive and motivation factors in determining the performance of normal and retarded children. Our general efforts have included the following areas of investigation: (a) further studies of the motivational factors in the behavior of both normal and retarded children, including social reinforcement effects, positive and negative reaction tendencies, the effects of success and failure histories on learning performance, outer-directedness and effectance motivation; (b) problem-solving strategies and their relation to a variety of the motivational factors described above, with a focus on the comparison of MA-matched normal and retarded children; (c) further studies of those circumscribed processes thought to differentiate retarded from normal intellectual functioning, e.g., cognitive rigidity and verbal mediation; (d) those environmental events which are experienced by many retarded individuals and which appear to influence their behavior, e.g., amount of preinstitutional social deprivation, institutionalization, the effects of failure experiences, and the nature of the environmental events which give rise to particular reinforcer hierarchies; (e) comparisons of institutionalized and noninstitutionalized retarded individuals of varying etiologies in order to determine how the preceding types of experiences might differentially affect the performance of such groups; (f) the effects of long-term educational intervention programs as well as day care programs in improving the performance of culturally disadvantaged children; (g) an extensive long-range evaluation of the effects of the Doman-Delacato treatment method for brain-injured retarded children, in comparison with other treatment methods for the retarded; (h) genetic aspects of effectance motivation; (i) biomedical correlates of retarded and disordered behavior.