This paper examines autopoietic theory with reference to functionally differentiated social sub‐systems, particularly law, science, and politics. It sets out to ‘test’ the practical relevance of autopoietic theory in relation to ongoing debates about post‐adoption contact and personal identity issues. Law has resisted social scientific pressure to regulate post‐adoption contact in the context of a social policy approach, which emphasizes the relationship between identity development and genealogical continuity. I argue that law's response to this pressure relates to the particular nature of adoption as this is expressed through legislation and case law. Law's refusal to intervene in post‐adoption contact reflects its self‐referential operations and its attempts to avoid epistemic entrapment by a social scientific discourse. Applying autopoietic theory to law's practical operations in adoption clarifies its explanatory value, provides a conceptual framework for understanding the relationship between law, politics, and social science and indicates areas that require theoretical refinement.