The near ubiquity of ingroup preference is consistent with the view that it is an automatic consequence of social categorization, possibly a basic foundation of intergroup relations. However, research with adults has demonstrated that automatic ingroup preference is notably absent among less dominant, less advantaged groups, an outcome predicted by System Justification Theory (Jost & Banaji, 1994). How basic is this tendency to justify existing social arrangements? Data from young children are crucial in addressing whether such an opposing orientation is itself a fundamental feature of intergroup social cognition. The developmental data summarized here suggest that knowledge about the relative status of one’s ingroup is absorbed and internalized sufficiently early in life, revealing system-justifying tendencies by age 5, the earliest age such questions have been examined to date. Across several studies summarized here young children from non-dominant groups failed to show an implicit ingroup preference, similar to their adult counterparts. We conclude that from an early age intergroup preferences are constrained by knowledge, implicit or explicit, about the relative status differences among groups and may suggest an orientation toward supporting existing social and political structures. The possibility that system-justifying tendencies may exist in even younger children remains open for future tests.