Why neighbors kill : an overview / Richard A. Vernon and Victoria M. Esses -- Individual factors -- Extreme harmdoing : a view from the social psychology of justice / Carolyn L. Hafer, James M. Olson, and Alexandra A. Peterson -- On the nature of contemporary prejudice : from subtle bias to severe consequences / John F. Dovidio, Adam R. Pearson, Samuel L. Gaertner, and Gordon Hodson -- Why neighbors kill : prior intergroup contact and killing of ethnic outgroup neighbors / Miles Hewstone, Nicole Tausch, Alberto Voci, Jared Kenworthy, Joanne Hughes, and Ed Cairns -- Why neighbors don't stop the killing : the role of group-based schadenfreude / Russell Spears and Colin Wayne Leach -- Societal factors -- When neighbors blame neighbors : scapegoating and the breakdown of ethnic relations / Peter Glick -- The influence of the threatening transitional context on Israeli Jews : reactions to Al Aqsa Intifada / Daniel Bar-Tal and Keren Sharvit -- Why do states kill citizens? or, why racism is an insufficient explanation / Patricia Marchak -- Synthesis -- Theories of genocide : the case of Rwanda / Howard Adelman -- Applying the unified instrumental model of group conflict to understanding ethnic conflict and violence : the case of Sudan / Victoria M. Esses and Lynne M. Jackson -- The origins of genocide and mass killing, prevention, reconciliation, and their application to Rwanda / Ervin Staub