He wrote his thesis on Jehovah's Witnesses under the direction of Jean Seguy. He holds a doctorate in psychosociology and a postgraduate degree in clinical psychology from the Institute of Paris 7. He is a member of the Group for the Study of Religions and Secularity at the National Center for the Scientific Studies in Paris, and a professor at the Charles de Gaulle University – Lille III. He published five books, many sociological articles in collective books, encyclopedias and journals and regularly participated in conferences of sociology. His contributions are mainly on Jehovah's Witnesses, healing churches and new religious movements.