Theorizing Ideological Diversity in Mass Violence Jonathan Leader Maynard, University of Oxford Introduction A paradox holds back understanding of perpetrators of mass violence. On the one hand, close empirical research has consistently emphasized perpetrators’ heterogeneity – the mix of motives and mind-sets found amongst members of the organizations and societies that engage in violence (e.g. Bartov 1994; Browning 2001; Browder 2003; Straus 2006; Gerlach 2010: 1-5). At the same time, however, both overarching theories of mass violence and summative characterizations of particular cases tend to homogenize perpetrator groups through causal stories which efface diversity (see also: Bloxham 2008: 204). Accounts of perpetrators have been orientated around, for example, bureaucratic compartmentalization (Bauman 1989), conformity to authority and peer-pressure (Roth 2005; Zimbardo 2007), willing ideological endorsement of violence (Goldhagen 1997; Weitz 2003; Semelin 2005), petty material self-interest and hooliganism (Mueller 2000), rational conflict decision-making (Kalyvas 2006; Wood 2014), or intense inter- group hate (Kaufman 2001; Suny 2004; Kaplan 2005). Frequently, these accounts are presented as opposing dichotomies: ‘willing executioners’ vs. ‘ordinary men’, ‘ideology vs. ‘self-interest’, or ‘greed’ vs. ‘grievance’ (Szejnmann 2008: 47; Matthäus 2007: 233; Bloxham 2008). Simultaneously, typologies sort cases into neat but essentialist categories: ‘ideological’ violence, ‘ethnic’ violence, ‘developmental’ violence, and so forth (du Preez 1994: 66-78). Few actually claim that these portrayals are apt for all perpetrators, and several theorists explicitly recognize that perpetrators act from varied and fluid motives (Kalyvas 2006: 24-25; Henriksen and Vinci 2008: 88; Karstedt 2012: 500). Indeed, such variation explains how all