The Yellow Vests movement has been a puzzle for social movement researchers, in that it seemed to be marked by a profound contradiction: a powerful and sustainable mass movement and the absence of what are usually considered to be the essential ingredients of a social movement. We argue that family is a key element in the Yellow Vest mobilization. This element, which has gone largely unnoticed, allows us to understand the reasons for popular anger, the way in which public policy measures can undermine solidarity mechanisms specific to the working and lower middle classes, and finally the ways in which the movement was organized. Beyond the case of the Yellow Vests, the role of family in social movements remains relatively under-studied and poses a challenge to the dominant approach to these research objects (Contentious Politics). Taking the family underpinning of mobilizations into account, helps bridging the gap between cultural practices and strategic action in social movement research.