This study investigated children's evaluations of peer group members who deviated from group norms about equal and unequal allocation of resources. Children, ages 3.5 to 4 years and 5 to 6 years (N = 73), were asked to evaluate a peer group member who deviated from 1 of 2 group allocation norms: (a) equal allocation of resources, or (b) unequal allocation of resources. Most children negatively evaluated deviant group members who espoused an unequal allocation, even when it benefitted the group, and explained their evaluation with reference to fairness. However, participants who liked unequal deviants (who advocated for an unequal allocation of resources) reasoned about group functioning and the benefits that an unequal allocation would have for the group. With age, children displayed social acumen by differentiating their own evaluation of the deviant act from their expectations of the group's favorability toward that deviant member. Findings revealed age-related increases for social acumen about group norms, as well as the use of fairness reasoning regarding resource allocation.