Although foremost among the benefits of cooperative learning is improvement of student academic achievement, additional affective benefits may further convince teachers that the value added by cooperative learning is worth the effort. This study examined the effect of an 8-month cooperative learning intervention on children's friendship choices in a Singapore elementary school. Four primary 5 classes, comprising 151 students, participated in the cooperative learning and four primary 5 classes, comprising 164 students, did not. All students were 11 years old. Between 76 and 81 percent of the students were Chinese, and the other ethnic groups represented were Indian, Eurasian, and Malay. Data were collected through sociometric surveys conducted before and after cooperative learning was used in social studies classes. The findings indicated that after 8 months of learning in cooperative groups, children in the experimental groups showed significant gains in percentage of cross-race choices of friends. Target diagrams of the sociometry survey indicated, however, that children still showed a distinct tendency to select friends among the same race. Also, getting pupils to work collaboratively in heterogeneous groups did not seem to produce gains in acceptance of low status children. Inherent in groupwork are problems of status and personality, and the teacher plays an important role in integrated rejected and neglected children. (Contains 18 references.) (KB)