People often behave as if category members share an essence, and essentialising a category in this way promotes inductive inference. Although natural kind categories have been predominantly studied, some social categories are essentialised and here we consider the inductive potential of religion categories for children in Northern Ireland. We asked seven-, nine- and eleven-year olds in Catholic-maintained, State-controlled and Integrated schools to decide whether pairs of children shared a property. We manipulated the degree of shared membership in religion, gender and musical categories. Overall, religion was much more inductively potent than gender, although older children and children from the Catholic-maintained school were more likely to use additional information about other categories when evaluating inferences. These results suggest that religion categories are a powerful basis for inference even in children as young as seven-years, and that religion categories may be essentialised in Northern Ireland.