This paper is a response to a Lecture by Vamik Volkan on Large Group Identity, Large Group Regression and Massive Violence. The author begins with a discussion about the definitions of some key concepts concerning social formations, such as group, organization and society. An explanation follows, concerning the way a traumatized society is likely to regress in typical ways. In particular, in the context of traumatogenic processes involving complex societies, cohesion is reduced and ethnic categories, usually not involved in social cohesion, become the basis of safety and social identity for traumatised people. Finally the author illustrates his Theory of Incohesion: Aggregation/Massification, seen as the fourth basic assumption, operating within the context of trans-generational traumatogenic, providing some examples of aggression typical of massification. Key words: massive violence, traumatized society, incohesion.