The study investigated the effects of a cooperative intervention designed to allow 40 academically handicapped (learning disabled or mildly retarded) and normal progress students (in third, fourth, and sixth grades) to work cooperatively on academic materials in improving social relationships between these groups of students. In the cooperative treatment, students studied mathematics in heterogeneous teams that were rewarded as a group for improvements in the performance of the individual members. This treatment was compared to a control treatment in which students worked individually on their mathematics work and were rewarded as individuals for improvement in performance. Results indicated that the cooperative techniques improved social acceptance, in that rejection of academically handicapped students was decreased, but friendships were not increased. Gains in academic achievement and self esteem were found for the combined sample of students in the cooperative learning treatment. (Author/DB)