This paper stresses the causes of the violent events provoked by masses as, for example, the fights among a group of soccer rooters, trying to contemplate the social and psychological conditions of possibility of those events. A first necessary condition to the manifestation of mass violence is the existence of an orderly distinction, characterized by the formation of a group identity summed up by affiliation signs: emblems, clothes, flags, tattoos, hair style etc. A second condition is the act of minority, once mass violence is always exercised against the minorities. The third condition is the exceptionality, because the time of the violence is an exceptional moment in the daily routine and there is an uncertainty of the everyday norms. The fourth condition refers to a certain culture of violence or to a knowledge of the appropriated manners from its manifestation, diffused by the media. Those four clauses do not explain mass violence completely, but they can help to build up a type of risk scale that could facilitate the prognostic, and even the prevention, in some specific cases.
Violence; Masses