We investigate whether beliefs about category boundaries as objective and category boundaries as natural are fused in intuitive conceptions or whether people distinguish between objectivity and naturalness. We conducted four studies with children (N = 270, ages 4-9, American) and adults (N = 360, American). In particular, we explored their judgments about animal (e.g., lions), artifact (e.g., hammers), and social-institution (e.g., police officers) categories. In every study, children and adults judged that social-institution categories were more constituted by social processes (and less by natural processes) than artifact categories. In contrast, they judged that social-institution categories were more objective (and less subjective) than artifact categories (this was significant in 3 of the 4 studies). Thus, children and adults distinguished which category boundaries were natural from which categories were objective. Our results additionally supported the conclusion that social-institution categories comprise a distinct conceptual domain from artifact categories.