In Study 1, 167 English children aged 6-8 or 9-11 evaluated peer English or French soccer fans that were loyal or partially disloyal. In Study 2, 149 children aged 5-11 made judgments about generic inclusion norms between and within competitive groups. In both studies, children's understanding of intergroup inclusion/exclusion norms (group nous) was predicted by theory of social mind (a social perspective taking measure) but not multiple classification skill. In Study 2, the number of groups children belonged to (an index of peer group experience) also predicted group nous. Supporting the developmental subjective group dynamics model ( D. Abrams, A. Rutland, & L. Cameron, 2003), children's experience and perspective taking help them make sense of inter- and intragroup inclusion and exclusion.