The effects of controversy and concurrence seeking and participation is age-homogeneous and age-heterogeneous cooperative learning groups were compared on achievement, achievement motivation, perspective-taking accuracy, and interpersonal attraction. In addition, the interaction among students within the cooperative learning groups was observed. One-hundred-twelve 4th-, 5th-, and 6th-grade students were assigned to conditions on a stratified random basis controlling for age, sex, reading ability, and homerooms. In all conditions, students studied two controversial issues with materials representing both pro and con views. In the controversy condition each small group was divided into two halves representing the pro and con sides. In the concurrence-seeking condition each small group studied pro and con materials on alternating days and were told to learn the material without arguing or disagreeing with one another. In the multi-age conditions 4th-, 5th, and 6th-graders were placed in the same learning groups, while in the single-age conditions students were placed in small groups with peers of the same age. The results indicate that controversy promoted higher achievement, greater achievement motivation, and more accurate perspective taking than did concurrence seeking. Multi-age learning groups had greater achievement motivation than did the single-age groups.