We demonstrate that the notion of a family 'constitution' (self-enforcing, renegotiation-proof norm) requiring adults to provide attention for their elderly parents carries over from a world where identical individuals reproduce asexually, to one where individuals differentiated by sex and preferences marry, have children and bargain over the allocation of domestic resources. In this heterogenous world, couples are sorted by their preferences. If a couple's common preferences satisfy a certain condition, the couple have an interest in instilling those preferences into their children. Policies are generally nonneutral. In particular, wage redistribution may raise, and compulsory education will reduce, the share of the adult population that is governed by family constitutions, and thus the share of the elderly population who receive attention from their children.