What makes the categorisation of a human collective morally relevant? How does the categorisation of individuals into groups affect their social status and treatment? This article provides an account of the moral relevance of social categories and assesses the status of “childhood” within this framework. It distinguishes morally relevant social categories (labelled as social groups) through three conditions: first, individuals are externally ascribed to the social category; second, the properties of the social category are reified through the social construction of (...) its definition; and, third, the social category predetermines the normative treatment owed to the individuals ascribed. The existence of these three characteristics in the construction of a social category entails that the individuals ascribed may be affected by unjust constraints and restrictions on their lives and choices, thus, requiring a re-evaluation of how their social grouping frames their status and treatment. The article claims that the “childhood” social category complies with the three conditions (ascription, reification, and normativisation). This implies that individuals categorised as “children” may suffer from unjust constraints and restrictions based on their social categorisation. (shrink)