This study focuses on the thought processes of 8 American third graders who are learning mathematics in a small-group cooperative learning model known as ''groups-of-four.'' Using stimulated recall methodology, thought processes from 2 groups, each consisting of 2 high-achieving and 2 low-achieving students, were obtained across 4 mathematics lessons in a single classroom. Results revealed that, although low achievers were active in the learning process, the small-group model did not reduce greatly the differential status effects between high and low achievers. High-achieving students assumed dominant roles in the undertaking of group tasks, in group decision making, and in the frequency and quality of contributions to group efforts. The findings suggest that low achievers are generally passive during small-group work. Suggestions for reducing passivity of low achievers are discussed.