Ingroup preferences when deciding who to include in 2 distinct intergroup contexts, gender and school affiliation, were investigated. Children and adolescents, in the 4th (9-10 years) and 8th (13-14 years) grades, chose between including someone in their group who shared their group norm (moral or conventional) or who shared their group membership (school affiliation or gender). With age, children displayed a greater ability to balance information about ingroup norms and group membership. Younger children were more likely to include an outgroup member who supported equal norms than were older children. Accompanying the choices made, there was a greater use of fairness reasoning in younger rather than older participants, and increased references to group identity and group functioning for school identification. There were no differences in ingroup preferences in the school and gender contexts for groups involving moral norms. Desires for equal allocation of resources trumped differences related to ingroup preference. For social-conventional norms, however, there was a greater ingroup preference in a school intergroup context than in a gender intergroup context. Thus, the results demonstrate the importance of context in the manifestation of ingroup preference and the increasing sophistication, with age, of children's and adolescents' group decision-making skills.