While it is possible to define the working classes as those that occupy a subordinate social position and whose cultural characteristics differ from those of the dominant social norms, it is more difficult to draw a line between families who fall into this category and those that do not. Likewise, empirical evidence shows that the working classes are by no means homogeneous, and the category must now be addressed in all its plurality. Starting from these observations and adopting an approach developed in research on the educational careers of working-class students, this article argues for a sociology of interconnection. After reconstituting the space of social positions by means of occupational, geographic, familial and economic variables provided by the students’ school files, the aim is to approach the social classes via configurations of social positions that each encompass a multitude of variables and their interconnections. The following configurations, all distinct from the middle and upper classes, are constructed: “pôle cité [familles immigrées],” or the cité group [immigrant families]; “pôle cité [familles fragilisées],” or the cité group [unstable families]; “élite ouvrière,” or the blue-collar elite; “familles populaires entre-deux,” or the in-between working-class families; and “petite fonction publique,” or junior civil servants. These configurations give greater intelligibility to the diverse modes of family socialization (and their contradictions) and the varied school careers of working-class students.