In enhancing a proposal by Luhmann, this contribution shows that it is possible to locate different types of systems between ‘face‐to‐face‐interaction’ and ‘society’: groups, organizations, families and protest movements. The common ground of these is that they use membership to attribute persons to the system or not. However, they differ fundamentally in regard to how they understand membership. In contrast to Luhmann's differentiation between interaction, organization and society, it is not only possible to imagine different types of interlocking systems but also coequal combinations of and transitions between the different types of social systems.