This paper presents a four-fold typology developed as a general theory of student motivation to stay in school and work hard at learning tasks. Each of the four-fold categories is described with an initial statement of the specific source of student motivation, an analysis of how the source fits in more general motivational theories, and how the experiences of poor and minority students make them especially at risk for lacking motivation. The four-fold categories that are discussed involve the opportunities that exist for success in schoolwork, the human climate of caring and support, the relevance of school to a student's community and future, and the help that is given in attaining freedom from personal problems. Analysis of a sample of dropout students is presented that shows activities designed to prevent them from dropping out are not up to the task. This is because the tasks are not basic or intense enough to reform the primary causes identified by educational theories of low student motivation to remain in high school. Reforms are needed to change the atmosphere from the current emphasis on controlling and sorting students to a new emphasis on supporting and caring for individual learners through major modifications in the roles and responsibilities of teachers and students, including services geared toward assisting students with outside problems. (Contains 27 references.) (GLR)