A review of theories of aggression and violence focuses on biological theories, psychodynamic theories, and social learning theory. A discussion of violence on trains in South Africa notes that according to the Human Rights Commission's Area Repression Report, 97 deaths occurred in train incidents as recorded for 1990 and 1991. The number of lives lost in train incidents in the first three months of 1992 has been reported as 126, thus surpassing the combined figure for the whole of 1990 and 1991. In 1992 a strategy for stopping armed passengers from boarding trains was developed and implemented. It involved active police and military support and included security fencing of all stations, adequate lighting, access control, and the active presence of the police. Communication between train drivers, the control room, and the police was improved to reduce the reaction time to dangerous situations. The police and the South African Defense Force traveled on commuter trains. All trains were regularly stopped and searched for dangerous weapons; toll-free telephone numbers were instituted for reporting crimes, and rewards were offered for useful information. Despite all efforts and measures, violence on trains continued unabated. A marked decrease in violence on trains was noticed in the first half of 1993, however, but showed a resurgence in the second half of 1993. At this point, commuters started becoming actively involved in apprehending attackers, in some cases identifying them to the police and in others apprehending them and handing them over for arrest. 5 figures and a 33-item bibliography