Kinship and alliance studies are a significant part of anthropological work related to the Arab and Muslim world, but they tend to focus primarily on rural and tribal societies rather than on contemporary evolutions (urbanisation, migrations, etc.). This article centres on the construction of these new anthropological objects and uses multidisciplinary data to define its field of study: Muslim family law reforms, demographic transition, the evolution of women's condition, etc. The rising age of first-time brides is an important variable. It is one of the general aspects of reforms in current Muslim states, and these reforms are having a certain impact on the French statute law. At stake, as is often the case in anthropological research, is the question of women's choice regarding marriage. In contemporary contexts, the fact that women continue to commit to proximity consanguinity marriages underlines the persistence of the social and cultural determinations of marriage.