The history of training on group dynamics-shows that the groups involved practically, have, surprisingly, been set to one side by clinicians, to the benefit of the study of therapeutic groups or focussing on the group. Whilst, however,:phenomena that take place in operational groups can have light shed on them, iri part, by the research carried out in the context of the latter, they do also present their own specific characteristics. We will attempt to show how, in particular, "operational" groups oscillate between overstructuring and understructuring of the organisation of work these two poles are the result of archaic anxieties and constitute frequent defensive modes: in the former case (of overstructuring), there is a battle against the emergence of the drive, of complexity, of chaos, that is controlled by bureaucratisation; in the latter case (that of understructuring), there is a fight against differentiation (echoing the maternal image), against recognition of competences and rivalry leading to a pseudo-democracy, The setting-up of a form of "unindulgent" everyday democracy that is more authentic and profound than that conceived by a non psychoanalytic psycho-sociology, depends on the comprehension of the processes at play at this level.