This review covers the psychological literature of the last 30 years regarding the personality and motivational characteristics of individuals with mental retardation. The first section is a brief historical review and critical examination of the various conceptual models and theories regarding personality and motivational processes in persons with mental retardation. The second section primarily addresses the implications of current mainstream psychological conceptions and theories regarding personality and motivational self-system processes for persons with mental retardation, including implications for individual educational programming. The third section provides a synthesis of the first two sections and provides an agenda for future research. The following models are reviewed: the rigidity hypothesis, social learning theories, self-concept theories, anxiety theories, and effectance motivation and intrinsic motivation theories. Consideration is also given to goal setting and goal value, self-efficacy, autonomy and self-determination, and intrinsic motivation and cognitive processes. (Contains approximately 360 references.) (SW)