Six classes of grade seven students (N = 181) participated in field research which explored the consequences of group outcome (successful, unsuccessful) for individuals learning mathematics cooperatively using Student Teams-Achievement Divisions. In addition, we explored the effects of within-class prior mathematics achievement (low, low-medium, high-medium, high) as well as attributional style (learned-helpless, mastery-oriented). The dependent variables were mathematics achievement, causal attributions, and self-concept. There were two interactions: Group Outcome × Attributional Style on achievement, and Within-Class Prior Mathematics Achievement × Group Outcome on achievement and self-concept. Learned-helpless students from unsuccessful groups learned significantly less than learned-helpless students from successful groups. Low prior achievement students from unsuccessful groups learned significantly less than low prior achievers from successful groups. In contrast, there was no significant relationship between group outcome and individual post-test achievement for mastery-oriented students or for students high in prior within-class achievement. © 1992.