Children and adolescents evaluated group inclusion and exclusion in the context of generic and group-specific norms involving morality and social conventions. Participants ("N" = 381), aged 9.5 and 13.5 years, judged an in-group member's decision to deviate from the norms of the group, whom to include, and whether their personal preference was the same as what they expected a group should do. Deviating from in-group moral norms about unequal allocation of resources was viewed more positively than deviating from conventional norms about nontraditional dress codes. With age, participants gave priority to group-specific norms and differentiated what the group should do from their own preference about the group's decision, revealing a developmental picture about children's complex understanding of group dynamics and group norms. (Contains 6 figures.)