Members of advantaged groups are more likely than members of disadvantaged groups to think, feel, and behave in ways that reinforce their group’s position within the hierarchy. This study examined how children’s status within a group-based hierarchy shapes their beliefs about the hierarchy and the groups that comprise it in ways that reinforce the hierarchy. To do this, we randomly assigned children (4-8 years; N = 123; 75 female, 48 male; 21 Asian, 9 Black, 21 Latino/a, 1 Middle-Eastern/North-African, 14 Multiracial, 41 White, 16 not-specified) to novel groups that differed in social status (Advantaged, Disadvantaged, Neutral-Third-Party) and assessed their beliefs about the hierarchy. Across five separate assessments, advantaged-group children were more likely to judge the hierarchy to be fair, generalizable, and wrong to challenge and were more likely to hold biased intergroup attitudes and exclude disadvantaged group members. In addition, with age, children in both the advantaged- and disadvantaged- groups became more likely to see membership in their own group as inherited, while at the same time expecting group-relevant behaviors to be determined more by the environment. With age, children also judged the hierarchy to be more unfair and expected the hierarchy to generalize across contexts. These findings provide novel insights into how children’s position within hierarchies can contribute to the formation of hierarchy-reinforcing beliefs.