The aim of this research project is to study religious rigorism and radicalization, in an interdisciplinary approach. The research skills of the team are pluri-disciplinary (sociology, visual anthropology, political sciences, psychology, Islamic studies and Arabic language). Our originality is to investigate how religious intensity, rigorism and (in)transigence, by analyzing life trajectories, modes of socialization as well as religious and non religious discourses. While refuting particularist and a fortiori pathological interpretation of these phenomena, we will analyze the individual and collective dynamics, in order to distinguish specific itinerary and reveal both differences and similarities between radicalism and rigorism. The project includes nine tasks, which are in strong interaction. The first four tasks mainly concern sociological analysis. First, an ethnographic fieldwork will be carried out in an organization involved in theprevention of radicalization. Collecting life course components as well as elements of evaluation will contribute to the definition effort of radicalization and religious rigorism. In addition, an interview survey on veiling and unveiling careers will allow to know more about the evolution of religiosities, especially intensive or rigorist ones. In the third taskwe will analyze written testimonies (mostly books) of rigorist and radical trajectories and their way out. The fourth task will investigate how the main (French) Muslim medias, Muslim organization and Muslim personalities (when invited by generalist medias) deal with rigorism and radicalization. Two tasks are concerned with film analysis, in conjunction with sociological and political analysis. The link between propaganda video emanating of jihadist organizations (or their publicists) and the radicalization processes will be analyzed. We will analyze their grammars and their effects while investigating which religious and political ressources are mobilized. Two tasks mainly concern psychological analysis: how does religious motives fit into life trajectories of young persons in difficulty or becoming violent extremists? What role does it play in psychological processes and in the way towards violent action? We will also investigate the self-image of the reported / radicalized person, with the aim of defining psychological profiles and to highlight subjective factors explaining the pull factors for some persons to a violent extremism linked to Islam. Finally the last task will be centered on the specific issues concerning social workers: how do they deal with the « religiousissue» and how does the detection of radicalization question their professional identity? We will develop theoretical tools in order to distinctly think radicalization and rigorism. While our approaches are innovative in each of our discipline, they will also be articulated throughout the project (each empirical fieldwork will be discussed with colleagues of the other disciplines), which will allow elaborating a theoretical framework and analytical tools for characterizing and distinguishing phenomena. The generated knowledge will be communicated at three levels: seminaries, workshops, conferences; articles in scientific, professional and mainstream journals/medias; professional and academic teaching. Being members of ESTES (social work school in Strasbourg), of EHESS Paris and of sociology and psychology faculties of Strasbourg University, we will develop specific pedagogic tools for sociologists, psychologists and social work. Finally, our results will be disseminated to a large public of professionals and civil society actors.