Children hold strong ingroup biases from a young age, liking ingroup over outgroup members and preferring them as social learning models. Simultaneously, children are also highly prosocial--both in their own helping behaviors and their avoidance of those who behave antisocially. This study explores how children of 2 age groups (4-5 and 7-8 years) react when these biases conflict; that is, when children's ingroup behaves antisocially. Children were assigned to a group and given a premeasure of liking to assess ingroup bias. They were then shown videos of the ingroup behaving antisocially and the outgroup behaving prosocially (or neutral controls). Children were then given the opportunity to choose which group to imitate and whether they wanted to change groups and then again given a measure of liking. Results revealed that older children were highly sensitive to pro- and antisocial behavior; when their ingroup was antisocial they were less likely to imitate them, reported liking them less, and were more likely to want to change groups. In contrast, younger children imitated the ingroup and reported liking them more regardless of their behavior and actually reported wanting to change groups less when their group was antisocial. This demonstrates a clear developmental jump between younger and older children in their capacity to weigh multiple strands of information when making decisions, and in particular it highlights the emergence of strong prosocial concern that persists over a drive to affiliate with an ingroup.