Gaining an understanding of intergroup relations and outgroup rejection is an important childhood development. Children learn about rejection by outgroups via their own experiences and external instruction. A comparison of the impact of experience and instruction on first-, third-, and fifth-grade children’s evaluations of rejection by outgroups in a minimal-groups paradigm suggests that the relative impact of experience and instruction differs as children age. In Study 1, younger children were more influenced by instruction, and older children were more influenced by what they experienced for themselves. In Study 2, younger children were more influenced by instruction, even when that instruction conflicted with what they experienced; older children were more influenced by their own experiences, even when those experiences contradicted what they were told to expect. These findings suggest that children begin learning about outgroup rejection through instruction but start to rely more on their own experiences as they age.