We model the cultural outcomes of ‘sons of the soil’ conflicts. These are conflicts between the local inhabitants of a particular region and migrants to the region, typically belonging to a dominant national culture. Our goal is to understand the conditions under which migrants assimilate into the local culture, or in which locals assimilate into the national culture. The model has two main actors: a national elite of a dominant ethnic group, and a regional elite seeking to promote the traditional culture of the sons of the soil. Both actors haveparallel strategies, viz. assimilating the other group into their culture, controlling the size of t he migrant population, doing both, or allowing market forces to determine outcomes. The model has three possible cultural outcomes: the culture tips to that of the sons of the soil; the culture tips to that of the migrant group; or the region remains bicultural, with each group retaining its own culture. We illustrate these outcomes through four cases: (i) Bengalis and Assamese in the Indian state of Assam; (ii) Russians and Estonians in the Ida-Virumaa county of Estonia; (iii) Tamils and Sinhalese in Jaffna and the Eastern Province of Sri Lanka; and (iv) Castilians and Catalans in the autonomous community of Catalonia in Spain.