Abstract: This work focuses on the potential effects of participatory processes in the interaction between civil society and the state. Our aim is to offer a proposal for the analysis and the operationalization of such effects in the relation of local authorities with the society: do participatory process produce any change as they promise from a normative point of view? Once specified the potential changes in these patterns of interaction, we consider two dimensions: the structural and the cultural level. After, we offer a proposal for its analysis and we develop several hypothesis (the coral reef effect, the democratic nucleation or the failed hybridization) which illustrate the mechanisms and conditions by which participatory processes affect the patterns of interaction civil society/authorities. The work closes with a discussion of factors affecting (modulating, enhancing or inhibiting) the possibility that participatory processes trigger theses effects.