Previous research suggests that preschool children expect members of social groups to share stable, inherent characteristics (e.g., Waxman, 2013). Here we explored the origins of these social-group based inferences by examining whether infants generalize food preferences across members of an arbitrary social group. Experiment 1 demonstrated that infants expected two individuals to share food preferences when they belonged to the same social group, but not when they belonged to two different social groups. Experiment 2 replicated and extended these findings to social groups that were labeled with adjectives instead of nouns. These results suggest that by 20 months of age, infants use social-group membership to make inductive inferences about the behavior of group members.