Is there a theoretical link between the gendering of life courses, worklife, and family participation? Is the "primary group" family to be considered part of the social structure? Is it passively exposed to its influences without any autonomy, is it rather an exclave from it, or is it an indispensable focus for understanding the social positioning of women and men? Most sociological analyses of social stratification, with their primary orientation on occupation, view the family-if they consider it at all-as hardly more than an alternative sampling unit, or at best as a rather secondary individual status variable ("marital status"). Conversely, family sociology pays more attention to social stratification, but here again, only few theoretical attempts focus the relationship between family and stratification. Life course research, if it is not practiced as an extension of the status attainment paradigm, has a bias similar to that of stratification research: the family is largely approached as a women's (problem) area, irrelevant to men's trajectories. In or-mille, participation professionnelle et genre. Il n'y a pas que les acteurs individuels qui pratiquent le "doing gender", les institutions font de même. I. Sociology: Looking at the "in-between" Most sociologists would agree that sociology is mainly about social relationships and their forms, and that such relationships exist not only between individuals, but also between social systems, sectors, groups, etc. Sociology's most general explanatory strategy could even be described as trying to find the reasons for the actors' social behavior not within them, but "around" them: in the social relations and institutional arrangements that frame their practical situations. However, this postulate encounters often decisive limitations, largely because of the social organization of sociology itself. Most sociologists are specialists of more or less traditionally defined areas: of the family, of international inequalities, of deviance, of the economy, of gender, of organizations, etc. Sociology can explain this state of affairs, but hardly justify it. 2 Typically, adult members of actual societies are members of a multitude of social fields, with different logics and structures. They have to cope with their multiple participations and with the conflicts and everyday problems they entail. How are we to understand the complexities of the actors' life-management if we con