Bringing self-determination theory to understand why intergroup behaviors are emitted, two studies were conducted to investigate how group norms and individuals' congruence with these norms predicted self-determination to pursue two types of intergroup behaviors (parity and discrimination). Experiment 1 (N = 97) manipulated ingroup norms in favor of parity versus of discrimination and assessed the behavior participants displayed (congruent or incongruent with the norm) and their motivations for emitting this behavior. The manipulated norms significantly influenced group members' behaviors. When the ingroup norm was parity, participants whose behavior was congruent with this norm reported more self-determination to emit this behavior. When the ingroup norm was prodiscrimination, participants whose behavior was congruent with this norm were less self-determined. Experiment 2 (N = 139) replicated and extended these findings in a more conflictual intergroup setting. Results are discussed in light of motivational and intergroup theories.