We sought to describe how prospective educators' choices of collaborative, cooperative, or individualistic interactions with group members and their willingness to apply unstructured effort into group functioning explained their levels of stress and self-evaluations of cooperative skills. Students (n=149) working in intact cooperative groups (n=32) over 12 weeks completed pre and post surveys and group processing reflections. Consistent with previous research, volunteers' reports revealed a positive effect of proactive interactions over passive, individualistic interactions. Yet, minimal amounts of group-related anxiety and sustained competence were most likely for those engaged in cooperative interactions with a willingness to address social justice. Programs emphasizing self-reflection and choice have the potential to produce higher quality outcomes for cooperative learning conditions.