From an investigation devoted to same-sex parents and an analysis of institutional reports on new reproductive technology (NRT), this paper studies the way in which contemporary French society is represented and how family relationships are formed. Parentage by adoption or by NRT is built through a principle of verisimilitude, whether by daily parenthood or by natural birth. Deviating from a standard which supposes the traditional family model (two biological parents, one male, one female), they reveal the tensions inherent in our descent, more particularly between biological and social conceptions of kinship, between the right of persons to maintain their anonymity and the right of the children to know their origins. All of this allows us to wonder about the current evolutions and choices of these last decades in the domain of kinship.