This introductory article to the thematic issue briefly situates the social and normative changes that have contributed to the transformation of the family and to the emergence of new family models in Quebec and elsewhere in the world. An overview of the recent history of the family institution in the West provides an opportunity to trace five dissociations between dimensions that were previously considered inseparable : 1) sexuality and procreation, through the legalization of contraception and abortion ; 2) conjugality and procreation, with separation and the rise of common-law unions ; 3) childbearing and parenthood, with the recognition of elective ties and parental roles ; 4) age and fertility, with the use of assisted reproductive technologies ; and 5) genetics and gestation, that is, the split within biological motherhood introduced by in vitro fertilization. The study of family diversity as a revelation of contemporary social norms offers a fruitful avenue for understanding the social changes taking place within the family and their impact on our representations of parenthood and family ties.