Abstract
Difficult life conditions give rise to scapegoating and ideologies that identify enemies and lead a group to turn against another. Conflict between groups and self-interest are additional instigators of group violence. Discrimination and limited violence change individuals and groups and can lead to an evolution that ends in mass killing or genocide. Certain cultural characteristics make this process more likely. The passivity of bystanders allows it to unfold. This conception, previously used to understand other instances of collective violence and further developed here, is applied to the exploration of the roots of genocide in Rwanda. To hall violence, once it begins, action by nations and the community of nations is essential. Reasons for bystanders' passivity and necessary forms of action are discussed. To prevent group violence may require the healing of wounds due to past victimization, reconciliation, and the resolution of conflict between antagonistic groups. Changes in elements of a group's culture are also important. Without prevention, great social changes and other contemporary conditions make frequent future group violence probable.