The ability to acquire and store generic information (that is, information about entire categories) is at the core of human cognition. Remarkably, even young children place special value on generic information, often inferring that it holds important insights about the world. Here, we tested whether children's assumptions about the nature of generic information guide their expectations about how widely known this information is. Across four experiments, 4- to 7-year-old children (N = 192) were presented with novel facts in either generic (e.g., "Hedgehogs eat hexapods") or non-generic (e.g., "This hedgehog eats hexapods") format and were asked whether other people (e.g., their moms, grown-ups in general) knew these facts. Overall, children were more likely to say that others knew the generic than the non-generic facts. In addition to highlighting the centrality of generic knowledge in early cognitive life, children's assumption that generic facts are widely known has implications for their social cognition and academic achievement, as well as for the process of language acquisition. (Contains 4 tables.)