What are the motivations of perpetrators of genocide and mass killing? How do those motivations evolve, and how do inhibitions against killing whole groups of people decline? What are the instigating conditions, the characteristics of cultures and societies, and the psychology of perpetrators and bystanders that contribute? How can violence be prevented, or, after violence has occurred, how can reconciliation be promoted so that new violence does not arise?

The influences leading to mass killing and genocide greatly overlap. The United Nations (UN) genocide convention defines genocides as “acts committed with intent to destroy in whole or in part, a national, ethnical, racial or religious group.” The genocide convention does not appropriately clarify the meaning of “in part”—that is, when killing some members of a group is genocide and when it is not—nor does it include the killing of political groups as genocide.

Among the many definitions of genocide that have been offered since the publication of the UN genocide convention, mine comes closest to that of Helen Fein (1993b, 24), who defined genocide as “sustained, purposeful action by a perpetrator to physically destroy a collectivity directly or indirectly, through interdiction of the biological and social reproduction of group members, sustained regardless of the surrender or lack of threat offered by the victim.” In my definition, “a government or some group acts to eliminate a whole group of people, whether by directly killing them or by creating conditions that lead to their death or inability to reproduce” (Staub 2011, 100). In contrast to genocide, I see mass killing as “killing (or in other ways destroying) members of a group without the intention to eliminate the whole group, or killing large numbers of people” without a focus necessarily on group membership (Staub 1989, 8).

How do we know what brings about such a large‐scale social process as a genocide or mass killing? Psychologists have studied genocide and mass killing directly only to a limited degree, because their customary methods of experimental research do not lend themselves to it. However, they have conducted wide‐ranging research on concepts and processes, such as devaluation of other groups, promoting positive relations through contact, more recently on “victim consciousness”—the varied effects of past victimization on people—and many others that are highly relevant to understanding the origins of mass violence as well as pointing to ways to prevention. Sociologists and political scientists (for example, Fein 1979, 1993, 2007; Harf 2003) have been the primary researchers on genocide, studying cases, sometimes at great depth (Fein 1979), sometimes more causally. In a rare study, Harff (2003) correlated a variety of existing conditions in many societies, like those I will discuss following, and the occurrence of mass violence in them.

Developing understanding of the origins and prevention of mass violence has to be interdisciplinary, since we must understand the psychology of individuals and groups, cultures, structures and institutions, and more. In developing an understanding of the roots of mass violence I have used an in‐depth case study approach. I studied the history of the groups involved and their relations, applying psychological and other social science concepts and prior research in analyzing this history. I derived principles and developed a conception of the origins of such group violence on the basis of some cases, and tested the conception by applying it to other cases. These cases ranged from genocide, to mass killing, and more recently to violent conflict, which is one of the instigating conditions for genocide (see Fein 1993a; Staub 2011). They include the Holocaust, the genocide of the Armenians, the genocide and autogenocide in Cambodia, the mass killing (disappearances) in Argentina, the genocide in Rwanda, and more recently also violent conflict such as the Israeli‐Palestinian conflict and the violence in the Congo, as well as terrorism (see especially Staub 1989, 1999, 2011). In writing about prevention and reconciliation I used psychological research; the writings of others in the field; my own and my associates’ work on reconciliation in Rwanda, Burundi and the Congo; and reports of other real‐world actions and experiences—for example, in Macedonia, Kenya, and Israeli‐Palestinian relations.

The following analysis in this essay draws extensively on Staub (1989) and especially Staub (2011); both of these books, and this essay, in turn, are informed by the work of others. I refer to a variety of instances, but I use the Rwandan genocide and the Holocaust—the genocide of the Jews—as primary examples.

Violence and its psychological and social bases evolve progressively. When the conditions that lead to mass violence are present and an evolution is in progress, one cannot predict which of these kinds of violence might be the outcome (Staub 2011). Moreover, mass killing, which makes later genocide more likely (Harff 2003), can be a way station to genocide. Therefore, prevention must focus on preventing increasing violence between groups, not specifically genocide. In actuality, a focus on genocide has become a problem. While the international community usually remains passive even in the face of genocide, it feels even less obligated to act in the face of mass killing or intense mutual violence. Arguing about definitions, nations and the UN tend to resist calling a genocide what it is in order to avoid the obligation to act.

Genocide is the result of a combination of influences. These include the conditions in a society, the characteristics of its culture, their psychological effects and the social processes they give rise to, the political system, the evolution of increasing violence and its psychological and social bases, and the passivity or complicity of internal and external bystanders. The more of these influences that are present and the fewer of those that can inhibit the evolution of events, the more likely that genocide will take place. Halting genocide once it begins and preventing mass violence when predictors suggest it is about to begin are essential tasks. However, early prevention is less costly in both human and material terms (Lund 2009; Staub 2011). It has rarely been used, but would certainly be more effective by inhibiting or even transforming the influences that lead to mass violence. It must become the aim of the international community.

1 The Origins and Prevention of Genocide and Other Mass Violence

Instigators or Starting Points and their Psychological and Social Effects

Difficult life conditions include severe economic problems, great political disorganization within a society, or great, rapid social changes and their combinations. Harff (2003) notes that poverty is not associated with genocide. However, case studies show that a deterioration of economic conditions can be a starting point for group violence (Davies 1962; Gurr 1970; Staub 1989). Moreover, inequality between groups, of which poverty is an important aspect, can give rise to social processes that lead to violence.

Difficult life conditions have an intense psychological impact on people. They frustrate basic, universal psychological needs for security, positive identity, feelings of effectiveness and control, a positive connection to people, autonomy, and comprehension of reality (Staub 1989, 2003, 2011). Difficult life conditions and the frustration of basic needs are starting points that can give rise to further psychological and social/group processes that satisfy these psychological needs to various extents, but they do not address the actual societal problems and begin an evolution toward group violence.

In response to the difficulties of life, individuals tend to turn to groups for identity, security, and belonging. They tend to elevate their group by devaluing other groups, and over time by acting to diminish others. They scapegoat another group as a way of protecting their self‐image or identity and maintaining their understanding of the world in the face of the helplessness created by intense life problems. Ideologies are developed that offer hope and a vision of a better life (nationalism, communism, Nazism, Hutu power in Rwanda, and so on), but they are destructive in that they identify enemies who must be “dealt with” (which often means, in the end, that they must be destroyed) in order to fulfill the ideology. Scapegoating and destructive ideologies turn the group against others. People can respond to the frustration of basic needs in positive ways—for example, by joining together with a constructive vision for a better future. But addressing the real difficulties of life is challenging and requires time and persistence. Instead, especially in the presence of certain cultural characteristics, people at times join in groups or turn to leaders who move them toward the destructive satisfaction of these needs through scapegoating and destructive ideologies. These initiate a group process that becomes a starting point for an evolution that can lead to mass violence (see Staub 1989, 2003, 2011; Faure 2008).

Most aspects of difficult life conditions have joined in well‐known cases of mass violence. There had been significant economic deterioration in Germany before the Nazis came to power, in Rwanda, in the former Yugoslavia, and even in the Darfur region of the Sudan. There was political confusion and political and social changes in these countries before mass violence began.

Conflict between groups, especially identity groups, is another instigating condition or starting point. The study of group conflict and genocide have been separate disciplines, partly perhaps because it was the Holocaust, the genocide of the Jews, that was the early and most studied case of genocide. There was no actual conflict between Germans and Jews preceding the Holocaust, except in the minds of the Nazis. However, group conflict, especially as it becomes persistent, intractable and violent, is often the instigating condition or starting point for genocide (Staub 2011).

Conflict can involve vital material interests, such as the need for territory as living space or for water as a resource. A material conflict of a different kind, between a dominant and a subordinate group in a society, has been a source of mass violence in many instances since 1945 (Fein 1993a). However, even when conflicts have objective material elements, they usually also have psychological elements, such as devaluation of the other group and mistrust and fear of the other. Moreover, over time, if conflict persists and becomes violent and intractable (not yielding to resolution), these psychological elements develop further and become more intense. The conflict frustrates basic needs. The other group comes to be seen as responsible for the conflict, as at fault, and as immoral, while one's own cause is seen as just and one's group as moral (Bar‐Tal 2000; Crocker et al. 2004, 2005; Kelman and Fisher 2003). These psychological elements, present in both groups and mirror images of each other, make the conflict especially difficult to resolve.

Frequently, issues of identity are present or increasingly enter. Groups with less power, access, privilege, and wealth often differ in ethnicity, race, or religion from those with more of these attributes. Differences in language and culture—values, beliefs, standards of conduct, perception, and interpretation of events, how much focus there is on particular basic needs such as connection, identity, or autonomy—can be further bases of differentiation. Demands by a less privileged group for greater rights, for the use of language or other aspects of identity, or for greater participation in society tend to be resisted by the more powerful. In the course of this resistance, elements of either group may initiate violence.

Here also, ideologies enter. The protection by the more powerful of their rights and privilege is usually supported by ways of seeing the world that justify their greater rights or privilege—by their intelligence, diligence, past accomplishments, or inherent superiority. Thus, dominant groups protect not only their rights and privilege but also their identity, their place in the world, and their comprehension of reality. Researchers have explored legitimizing ideologies, such as a social dominance orientation that justifies the dominance of those with power and privilege (Sidanius and Pratto 1999), and system justification, which justifies whatever social arrangements exist (Jost et al. 2004), and found that they have wide‐ranging influence.

Conquest was common in earlier times, and mass killing was associated with it (Kiernen 2007), driven by material interest or the desire of nations and their leaders to elevate themselves. In modern times, superior groups have engaged in practices, whether direct violence or creating conditions that destroy a group's environment and what that group needs to sustain its life, to exploit land for its natural resources or for other uses. Indigenous groups have suffered greatly, and have sometimes been extinguished, through development practices in areas where they lived (Totten et al. 1997). In such conflicts, driven by self‐interest, difficult life conditions are not necessary as an instigator. However, devaluation of a group and other influences that contribute to mass violence are invariably present.

Genocides often take place in the context of war. Sometimes genocide is directed against the opponent in the war, as in the civil war in Rwanda (where, at the time the genocide began, there was a cease‐fire). At other times, the victim is a party not involved in the war, as in the Holocaust. War represents significant evolution of violence, which makes further violence easier. In addition, war can be a cover under which it is easier to turn against a group toward which intense hostility has already evolved and/or that has been identified as an ideological enemy.

Group conflict and difficult life conditions often join as instigators. Difficult life conditions can intensify the dissatisfaction of less privileged groups. However, it is not necessary for both conditions to be present. Before the Holocaust there was no actual conflict between Germans and Jews, the latter a peaceful minority in Germany, except in the mind of the Nazis. In contrast, there was a long history of conflict between Hutus and Tutsis in Rwanda. The difference between Hutus and Tutsis is a combination of historical difference in wealth and power and, to an unclear degree, ethnicity (des Forges 1999; Mamdani 2001; Staub 2011). The clear difference is that of identity. Before 1959 the Tutsis were dominant, their dominance enhanced, and the Hutus oppressed under Belgian overrule. After a revolution in 1959, the Hutus in power devalued, discriminated against, and occasionally engaged in mass killing of Tutsis. Before the genocide in 1994 there were severe economic problems, political chaos, and a civil war.

The Evolution of Destructiveness

Intense violence does not just spring up out of nowhere: hostility and violence evolve and intensify. This evolution is avoided or halted if all subgroups of a society work together to address difficult conditions of life or if groups are committed to resolve conflict through negotiation and mutual concessions. Such constructive modes of fulfilling needs and addressing differences often are not used. Instead, groups engage in scapegoating, create destructive ideologies, blame one another for their conflict, and begin to harm one another. This can start a psychological and behavioral evolution. Individuals and whole groups “learn by doing.” As they harm others, perpetrators and the whole society they are part of begin to change. This evolution can be one‐sided or, in the case of violent conflict, mutual.

People who harm others have to justify their actions. They devalue those they have harmed, and they get accustomed to or habituated to discrimination and violence against them. Both perpetrators and passive bystanders, who know what is happening but take no action against it, tend to do this. They engage in just‐world thinking—believing that the world is a just place and that those who suffer must somehow deserve their suffering (Lerner 1980). Increasing devaluation leads to moral exclusion, the exclusion of the victimized group from the moral realm—that is, from the realm of people to whom moral values and standards apply (Fein 1979; Opotow 1990; Staub 1989, 2011). Perpetrators of violence may also replace moral values that protect people's welfare and life with other values, such as obedience to authority or loyalty to the group. As a final step, there may be a reversal of morality: killing members of the designated enemy group becomes the right thing to do. As the evolution progresses, individuals change and the norms of social behavior change. New laws and new institutions may be created to support actions against the victims, such as special offices to deal with them and paramilitary groups (Staub 1989, 2011).

In some cases, one can see a continuous progression of this kind. But often there are breaks—periods of time when there is no further evolution. However, the elements that have developed remain part of the deep structure of the culture, and as conditions change, the evolution can restart. For example, in the Holocaust, the Nazis used both devaluative propaganda against Jews and symbols, such as the yellow star they were forced to wear, that were used in much earlier historical periods. In Turkey there was a mass killing of Armenians from 1894 to 1896, followed by the genocide in 1915–1916. In Rwanda there was repeated mass killing of Tutsis before the genocide. Earlier mass killing is especially dangerous, since it makes mass killing and genocide conceivable and psychologically accessible (Staub 2011; see also Harff 2003).

Cultural Characteristics that Make Destructive Modes of Need Fulfillment More Likely

Certain characteristics of a culture make it more likely that in a difficult time, or in the face of group conflict, the psychological reactions and events that have been described will take place.

Us and themthinking, cultural devaluation, and ideologies of antagonism are core influences in mass violence. The devaluation can be less intense (the other is lazy, less intelligent, and so on) or increasingly intense (the other is manipulative, morally bad, dangerous, an enemy that intends to destroy one's own group). Laboratory research shows that even when people are not a threat, just hearing them derogated can lead to more harmful actions against them (Bandura et al. 1975). Cases studies of genocides suggest that groups that are seen as morally bad or a threat, especially if they nonetheless do relatively well in a society—such as the Jews in Germany, the Tutsis in Rwanda, and the Armenians in Turkey—are especially likely to become victims (Staub 1989).

The tendency to categorize people into “us” and “them” is strong. It can have trivial bases. Identities can be formed around small differences. Sometimes hostility against those who differ only slightly from one's own group is especially intense. Anti‐Semitism may have developed out of the need of early Christians to create a separate identity. The Bolsheviks hated the Mensheviks, who differed from them only in limited ways, and heretics have been intensely persecuted.

Sometimes two groups develop intense mutual hostility. They see the other as their enemy and themselves as an enemy of the other. Being an enemy of the other becomes part of their identity. This makes intense violence easier and more likely. An ideology of antagonism can develop as part of an evolution of violence, or it can be a relatively stable aspect of groups’ orientation to each other that has developed over an earlier historical period (Staub 1989, 2011).

Overly strong respect for authority in a society makes it difficult for people to deal with instigating conditions. Accustomed to being led, they are more likely to turn to leaders and ideological groups. They are unlikely to offer opposition when their group increasingly harms another group. They are also more likely to follow direct orders to engage in violence. Nazi Germany, Rwanda, and most other countries in which genocide or mass killing were perpetrated were countries where the culture, child‐rearing practices, and hierarchical social organizations fostered and maintained strong respect for authority.

A monolithic (versus a pluralistic) culture and autocratic political systems facilitate destructive responses to difficult life conditions or group conflict. The more varied are the values in a society and the more freedom there is to express them, the less likely is a genocidal process to evolve; people will be more likely to oppose the evolution toward genocide. This is one aspect of pluralism. Another is that members of all groups in a society have the right and the possibility to participate in the public domain (Staub 2011)—that they have a voice, access to the media, can participate in business life and political processes. Pluralism and authority orientation are a matter of both culture and the system of government. Mass killing—violence against large numbers of people who may be members of various identity groups but who are regarded as political opponents or enemies, as well as mass violence of other kinds—is more likely in autocratic political systems and can be pursued under such systems as government policy (Fein 2007; Rummell 1994). Democracies are unlikely to engage in genocide; this is especially true of mature democracies, with civic institutions that have deepened democracy. However, the U.S. government and other democracies have supported repressive dictatorships that engage in violence against their people. They also at times engage in violence or war, especially against nondemocratic countries (Staub 2011).

Unhealed wounds from past victimization or suffering have severe psychologically effects. Groups often focus on past trauma, which becomes a lens through which they see the world (Volkan 1997, 1998). When a group has been victimized in the past, healing is important to prevent further violence. Without healing, the group will continue to feel diminished and vulnerable and see the world as a dangerous place. At times of difficulty or in the face of new conflict, such groups may feel an intense need to protect themselves. They may engage in what they think of as necessary self‐defense, which, instead, could be the perpetration of violence against others (Staub 1998, 2011).

A history of aggression in a society as a means of resolving conflict makes violence accessible as a way of responding to new conflict or to the hostility that evolves from difficult life conditions. Both statistical analysis of a large number of cases (Harff 2003) and case studies (Staub 1989, 2011) indicate that past violence in a society makes renewed violence more likely.

Witnesses’ or Bystanders’ Roles in Worsening Identity Conflicts

The passivity of bystanders, of witnesses who are in a position to know (but often close their eyes to) what is happening and are in a position to take some kind of action, greatly encourages perpetrators. It helps them believe that what they are doing is right. Unfortunately, bystanders are often passive. By continuing with business as usual, both internal and external bystanders often become complicit in the violence.

Internal bystanders participate in the discriminatory system set up against victims. Like perpetrators, they tend to justify their passivity by devaluation, just world thinking, and other methods. They also undergo an evolution and contribute to the evolution toward violence in their group or society. These bystanders, who are members of the same society as the perpetrators, have also internalized the cultural devaluation of the victim group and the respect for authority. In addition, it is difficult to oppose one's group, especially at a time of severe life problems or group conflict. To reduce their empathy, which makes them suffer, and their feeling of guilt, bystanders often distance themselves from victims (Staub 1989, 2011). As they change, some bystanders become perpetrators (Lifton 1986).

External bystanders, outside groups and other nations, also tend to remain passive, continue with business as usual, or even support the perpetrators. For example, U.S. corporations and those of other countries continued to do business in Germany during the 1930s in spite of the increasing persecution of Jews and the brutality of the Nazi regime against all those it saw as enemies. France supported the Rwandan government militarily during the civil war, in spite of the tremendous hate propaganda against the Tutsis and the occasional killing of large numbers of Tutsi civilians, and continued to support the government during the genocide (Malvern 2004). France also helped the perpetrators escape when the genocide was brought to an end by a Tutsi‐led rebel group and allowed them to take their arms with them, including heavy equipment. The perpetrators’ subsequent attacks on Rwanda were an important reason for the war in neighboring Zaire, renamed the Democratic Republic of the Congo, which has continued for many years, by 2011 resulting in close to 6 million deaths. Nations have traditionally not seen themselves as moral agents. They have used national interest—defined as wealth, power, and influence—as their guiding value. Sometimes old ties to a country and to a particular group within it lead some nations to support the perpetrators—as in the case of French support for the Rwandan government—rather than the people who are being harmed (Staub 2011).

Leaders and elites have important roles in shaping and influencing societal conditions. To a large extent, it is the inclinations of populations, the result of conditions in the society, group conflict, and the characteristics of culture, that create the possibility and likelihood of mass killing or genocide. People select or turn to leaders who respond to their inclinations and fulfill their needs at the time. On the other hand, leaders already in power or arising leaders—including leaders of ideological movements—are both themselves affected by existing conditions and use these conditions for their own purposes.

These leaders can attempt to deal with problems in a society and the causes of conflicts between groups using peaceful, constructive means. Or they can look for enemies and engage in actions that instigate violence. They can scapegoat and offer destructive ideologies, using propaganda to intensify negative images and create or strengthen hostility toward potential victims. They can create hate media, paramilitary groups, and other institutions to promote hostility and serve violence. Often leaders are seen as doing these things purely to gain support or enhance their power. For prevention, it is important to see them as members of their society, impacted by life conditions and group conflict and, at least in part, acting to satisfy their own and the population's basic psychological needs. However, there can be truly destructive leaders as well. Both leaders and other perpetrators can be—sleepers (Steiner 1980), people who act in normal ways in normal times but have an inclination to hostility and violence that can emerge at times of social chaos and disorganization (see also Zartman 1989).

Prevention of Intense Violence between Groups

Halting Violence and Late Prevention.

When there has already been significant violence or when the predictors described above are present at a significant level so that large‐scale violence can be expected, decisive action is essential. With regard to such late prevention, as well as early prevention, important questions are what is to be accomplished, how it is to be done, and who is to do it.

In responding to a crisis and halting already occurring mass violence, actions that aim at prevention include threats to leaders/countries, sanctions and boycotts, and, as a last resort, military intervention. Often none of this is done, or it is done too late or ineffectively. For example, nothing was done in Rwanda—except for many countries sending military personnel and aircraft to evacuate their own citizens, thereby telling the perpetrators that they could do as they wished to their own citizens (Hatzfeld 2003; Malvern 2004).

Sanctions and boycotts often do not work because some countries do not participate in them or abide by them. Also, while they can create great suffering in the population, as the boycott of Iraq under Saddam Hussein did (Richardson 2006), leaders often do not care enough about the population and are themselves not sufficiently affected to change their policy. A newer approach to sanctions and boycotts is to focus on the leaders: their finances, bank accounts, and ability to travel. Broad‐based sanctions may be more effective in countries that have a substantial industrial/business class whose interests are affected, and who can exert influence on the leaders and the political system, as was the case in South Africa. In addition, in South Africa, there were internal actors fighting the apartheid system, which has been found to be important for the effectiveness of sanctions.

At times, military intervention is essential. As the Task Force on the Prevention of Genocide, chaired by Madeleine Albright and William Cohen, indicated (Albright and Cohen 2008), military intervention is a not an either/or matter. Military exercises in a neighboring country can discourage leaders and perpetrators. The presence of a sufficiently large peacekeeping force can do the same. In Macedonia in 2001, after fighting between the Albanian minority and the government forces, peacekeepers were helpful in creating time and space to address the issues between the parties. However, they may also have been effective because a number of early intervention processes were ongoing. These included efforts to overcome hostile attitudes in the population through newspaper articles showing the similarity in the lives of the members of the different ethnic groups in the country, as well as activities that prepared the ground for the government to create new laws addressing the grievances and enhancing the rights of the Albanian minority (Burg 1997; Staub 2011).

Often, to be effective, peacekeepers must have UN permission, training, and equipment to fight. But fighting has usually been contrary to UN rules and practice. Peacekeepers have been sent to inhibit violence by their presence or to keep peace already agreed to, at least on paper. When violence flared up, they were not to act and often could not even defend themselves. It has become increasingly clear that peacekeepers—perhaps paradoxically, given their name, but essential, given their intended function—need to be able to fight to keep the peace. Moreover, for military intervention, as the action of last resort, a ready rapid strike force ought to be created. This needs to be a standing force under UN control, since nations are often reluctant to contribute their own soldiers even in an extreme crisis. While there is international resistance to creating such a military unit, it is essential.

Varied forms of preparedness are necessary to halt ongoing violence or to respond to crises. The Task Force Report indicates that there is no agency in the U.S. government to address crises of genocide or mass atrocities and no plans of action that could be drawn on in emergencies. This is certainly also true of other countries.

While threats, sanctions and boycotts, peacekeeping, and military intervention may at times all be necessary, even at a late point, human interaction, engagement, dialogue, negotiation, and mediation need to be attempted. In cases of late prevention, for preventive diplomacy to be effective, high‐level actors must be involved. In Kenya in 2008, following disputed election results, as violence between groups began, the involvement of the former secretary‐general of the UN, Kofi Annan, foreign ministers of various countries including the United States, and presidents of neighboring countries led to a speedy agreement on power sharing (Carson 2008). Although this agreement did not solve long‐standing problems, it brought the violence to an end. Such conflict management is essential as a prelude to conflict resolution. Very‐high‐level leaders, such as the U.S. president, are usually reluctant to get involved this way, presumably concerned that failure to resolve a crisis or halt violence will reflect badly on them. But their involvement can make a huge difference.

UN officials ignored the entreaties of General Romeo Dallaire, the head of the UN peacekeeping force who was warned about plans for the genocide in Rwanda, to be allowed to search for and destroy the machetes that were the intended means and eventually became the primary means of genocide. What might have happened if, at that time, under the auspices of the UN or of several individual nations, influential external leaders had engaged Rwandan leaders? And what might have happened if they had engaged France, the unconditional supporter of the Rwandan government (Malvern 2004) or if President Bill Clinton had brought together leaders of powerful countries, as well as those of neighboring states, and Serb, Croat, and Bosnian leaders, when violence in the former Yugoslavia began (Staub 2011)? Powerful leaders, especially if they are also respected and trusted, can have substantial influence in many cases.

Early Prevention.

Early prevention can be initiated and fostered by external bystanders, but internal actors are crucial. Early prevention has to address the population, the leaders, and those in the society, such as the media, that can have both upward and downward influence (Lederach 1997; Staub 2011). One aim of early prevention is the creation of structures that will make violence less likely. These include structures in which people work together to achieve shared goals or democratic institutions that promote the participation of everyone in society and their fair treatment. However, even though, to some degree, institutions have a life of their own, it is people who create, maintain, and change institutions. The motivation to shape or create institutions that can prevent violence and promote peace requires psychological changes in people.

Early responses to difficult life conditions can limit their instigating power. The policies developed by the Roosevelt administration after the Great Depression limited its economic impact on people. By providing people with jobs, these policies also increased the sense of a shared community, with people facing their difficulties together and feeling that the country cared about them. Poor countries need financial help to address deteriorating economic conditions. However, their governments can still do a great deal to give people a sense of shared community and help to satisfy psychological needs for identity and connection, and through that to create a feeling of security.

Practices to create more positive attitudes toward the “other” are crucial for the prevention of violence. This is the case when there is “progress” in the evolution of violence against a potential victim group, such as increasing public devaluation and discrimination, as well as when there is increasing conflict between identity or interest groups.

One method for creating a more positive attitude is to promote contact between members of groups. A great deal of research in social psychology, and practical projects bringing members of hostile or prejudiced groups together, show that significant, deep contact creates more positive attitudes (for overviews, see Pettigrew and Tropp 2006; Staub 2011). Having people work together to bring about outcomes beneficial to both groups, through joint projects in the service of goals superordinate to their separate goals, is especially useful. The more conditions are created for such contact to occur naturally, the better. Hindus and Muslims working together in institutions, and having developed good working relations, have acted together in potentially explosive situations to prevent violence (Varshney 2002). In schools that introduce cooperative learning, the deep engagement by majority and minority students with each other in the course of working together on tasks create positive attitudes and interactions (Aronson et al. 1978). Anstey and Zartman (this volume) note, however, that contact between members of different groups living next to each other can also develop hostility. There are many reasons that people devalue each other, including differences in physical characteristics, culture, values and ways of life, or one group exploiting another and justifying their relationship by devaluation (Staub 1996). People belonging to different groups often have very superficial contact (Deutsch 1973); living next to each other without deep engagement, people can respond to differences and devalue each other more easily. Humanizing others by what we say about them, and deep contact are both essential to overcome devaluation.

Dialogue is an important form of contact. One aspect of dialogue is addressing practical issues between groups—for example, in problem‐solving projects and workshops (Kelman 2008). But a crucial aspect is to increase mutual understanding and trust, which then increases the ability of groups to resolve practical issues and abide by agreements.

Humanizing the other is extremely important in changing attitudes. Leaders can do this by the way they talk about the other group and the way they engage with its leaders. Schools can do it by treating children from all groups with respect, insisting that the children treat each other with respect, and by what they teach about each group. In Macedonia, one of the constructive preventive actions was having journalists from different ethnic groups come together, write about the lives of people in each of the groups, which were quite similar, and then publishing their articles in the newspapers of each ethnic group. Their articles humanized all the groups, and their contact with each other affected their later writing about group relations (Bug 1997).

Healing the wounds of past victimization and certain collective memories make unnecessary violence by victims and renewed violence by perpetrators less likely. After group violence, healing is best approached through group activities, since violence and the experiences of victimization are group based, and often the societies are communal (Rosoux 2001; Staub and Pearlman 2006). The practices of healing can include testimonies by people of what has happened and shared commemoration in which all members of society participate. Too intense a focus on the painful past can be harmful, contributing to the development of a “chosen trauma”; in addition to grieving about the past, looking to a better future is valuable. Acknowledging the role of rescuers, members of the perpetrator group who have attempted to save lives at times of violence, can contribute to healing by both survivors and members of the perpetrator group. So can justice processes and understanding the roots of violence.

Even in cases of violence by one group against the other, the perpetrators tend to blame their victims. In the case of mutual violence, usually each group blames the other. They may emphasize different events in the past and differ especially in their interpretation of events. Coming to some form of shared view of history is an aspect of the resolution of conflict and makes new violence less likely (Rousoux 2001; Zartman and Kremenyuk 2005; Staub 2011). This requires, in part, changes in a group's collective memory. Healing from past trauma makes this easier. The work of historians can be important. In Israel, the original collective memory held that Palestinians left during the war of 1948 to escape the violence or were encouraged by their leaders to leave for the duration of what they believed would be a short war. A group of new historians showed that this was partly true but also that many Palestinians were expelled (Morris 2004). This new history slowly spread throughout Israeli society. In the wake of group conflict, commissions can be created to explore actual history and collective memory and to negotiate a shared history—which can require compromises (Staub 2011).

Understanding the origins or influences leading to, and avenues for the prevention of, genocide and group violence based on identity and/or interests, can be a significant contributor to effective prevention. In work in Rwanda, in its first phase, my associates and I conducted workshops/trainings with varied groups (facilitators who work with community groups, national leaders, community leaders, and journalists). Two important elements of these trainings were promoting understanding of the influences that lead to group violence, along the lines described in this chapter, and describing its traumatic impact on people. Further elements were considering avenues to prevention as well as reconciliation, which can be both an aspect of prevention between hostile groups and an avenue to the prevention of renewed violence.

In trainings with mixed Tutsi/Hutu groups, participants heard lectures and extensively discussed ideas, which they intensely engaged with as they applied them to the genocide in Rwanda. We used examples from other settings, but they themselves explored the extent to which the influences we have discussed as leading to mass violence were present in Rwanda. This process seemed to lead to a deep experiential understanding of the influences leading to mass violence (Staub et al. 2005; Staub 2006, 2011; Staub and Pearlman 2006; Wolpe 2005; Zartman and Kremenyuk 2005). The nature of this training, discussing events of the past in relation to concepts, rather than focusing on who did what, creates positive engagement between members of hostile groups and limits the intensity of feelings. It could serve as a valuable preparation for conflict resolution practices, dialogue, and negotiation.

As an extension of these trainings, in collaboration with La Benevolencija, a Dutch nongovernmental organization (NGO), we developed educational radio programs, using the same conceptual material and approach, first in Rwanda and later in Burundi and the Congo as well (Staub 2008, 2011; Staub et al. unpublished). There have been several types of radio programs in each of these countries, including informational programs and programs about justice. But a major type was radio drama, with educational content embedded in the story. In Rwanda, the program “Musekeweya” (“New Dawn”) centered on a conflict between two villages, with all the elements of origins, and then, progressively, with elements of prevention and reconciliation infused in the story. Evaluation of the effects of the original training (Staub et al. 2005) and of the radio drama in Rwanda (Paluck 2009; Staub and Pearlman 2009; Staub et al. 2010; Staub 2011) showed changes in attitudes, such as a more positive orientation toward and more empathy with members of the other group, reduced trauma symptoms, and conditional forgiveness, as well as changes in behavior, such as more independence of authority and more willingness to speak out and engage in public discussion.

The way the press writes about events, and educational programs on radio and television, can inform people and make them aware of their potential influence as active bystanders. They can make it more likely that people will not passively stand by, but engage early, before destructive ideologies become extreme and violence evolves, and before action becomes highly dangerous. While each person has limited capacity to change the direction of a group, and while it was once difficult for people to exchange information and organize themselves, the Internet has made this easier—both for harmful actions, such as terrorism, and for positive action.

Constructive ideologies are an important means of prevention. The power of ideas is great, especially affect‐laden ideas. Positive visions of social arrangements and human relations can give people hope in difficult times and in the midst of conflict. Constructive visions that embrace all groups and allow everyone to participate in their fulfillment can inhibit/overcome the power of destructive ones. Such a constructive vision for Israelis and Palestinians can be an economic community that improves people's lives materially and also creates peace (Peres 1995; Staub 2011).

In Rwanda, the current leaders have offered a seemingly constructive but problematic vision: We are all Rwandans; there are no Hutus and Tutsis. They have strongly discouraged the use of the latter designations and public discussion of issues between the groups. However, identity groups tend to be deeply committed to their identity, and a common groups membership may be best promoted by also allowing subidentities as members of different ethnic groups (Dovidio et al. 2009; Staub 2011). Thus, a more effective, constructive vision would be to advocate a future in which people consider themselves and each other Rwandans, but allow and encourage pluralism and the discussion of past differences and current issues. In such a framework, hate speech, which was a strong contributor to and background for the genocide, could still be prohibited. This may be a useful framework but it is not an easy task, especially for a minority group in power that is deeply wounded by a recent genocide against it, and which itself has engaged in mass killing of members of the other group after the genocide (particularly of Hutu refugees in the Congo) and feels defensive about this, and with perhaps substantial elements of the majority still hostile.

Constructive groups provide a positive means to satisfy basic needs and an alternative to identity groups focused on conflict and to destructive ideological movements. In difficult times, people turn to groups—their ethnic group or another established identity group, or to ideological groups—that are all too often destructive. Membership in such groups and the ideology they develop help fulfill needs for security, connection, and identity, as well as promote effectiveness as people engage in the fulfillment of ideologically prescribed goals. Constructive groups that are inclusive in membership and have positive goals, whether small and limited or large‐scale social goals, would provide important alternatives in difficult times. There are many such possible groups: those working together on economic projects, on social change projects, and others. Stable groups of this kind in a society, or groups created in response to life problems, make it less likely that people will turn to destructive ideological movements (Staub 2011).

Training about the roots, the psychological impact, and the prevention of violence is important to provide for leaders. In Rwanda, we provided such training in workshops with leaders. We then had them engage in exercises, in particular to evaluate whether policies the government had just introduced or was planning to introduce would make violence more or less likely. The government ministers, heads of national commissions, advisors to the president, members of the Supreme Court, and others who participated deeply engaged with these trainings (Staub and Pearlman 2006; Staub 2011). Howard Wolpe of the Woodrow Wilson Center and his associates had Tutsi and Hutu leaders in Burundi engage with each other, begin to know and develop some trust in each other, and learn skills of effective interaction (Wolpe 2005; Wolpe and McDonald 2008). Such trainings can bring about changes in leaders’ policies and practices, their attitudes toward the other group, and their ability to engage in dialogue and resolve practical issues. If such trainings became regular, normal activities for leaders, they could make an important contribution to prevention of violence.

Development practices and democratization are widely seen as means of prevention. But it is important for them to be equitable and to diminish rather than increase the difference between more and less powerful groups (Hamburg 2007). Democracy promotes pluralism and moderates respect for authority. But it is mature democracies in which internal violence is especially unlikely. Mature democracies require effective civic institutions and broad public participation. For these to be created—for example, a justice system that treats people equally—requires some of the psychological changes—for example, in attitude toward the other—that I have discussed.

The Who of Genocide Prevention

In addition to the genocide convention, and other conventions and principles that the UN has developed to protect human lives and rights, in 2005 the Principle of Responsibility to Protect was approved by the UN General Assembly, as discussed in Franz Cede's chapter. This makes it the responsibility of nations to protect their citizens. If they do not, other countries become responsible to engage and intervene. Unfortunately, when and how the principle is activated, and mechanisms for action, are still lacking. The UN secretary‐general has appointed Francis Deng as under‐secretary‐general for the Prevention of Genocide, with an active mandate.

If the danger of genocide and mass killings, and the identity group conflicts that can lead to them, is to be reduced and then eliminated, the UN and its member states must be important actors in preventive efforts. The effectiveness of the UN depends to a large extent on the behavior of its member states. Other international NGOs, as well as many national NGOs, can contribute to early prevention. But how can they be engaged?Albright and Cohen's (2008) Task Force suggests for the United States a complex high‐level government interagency group to coordinate the U.S. response. However, there ought to be very‐high‐level officials in the U.S. government and those of other countries who are directly responsible for gathering information and initiating preventive actions. High‐level Central Office(s) for the Prevention of Mass Violence ought to be created in foreign ministries (Staub 2010). Only if it is the primary or sole responsibility of officials with sufficient power, is it likely that they will be concerned enough about problems in faraway countries, have the determination to generate the political will for action, and develop ways to initiate effective action.

The Task Force, whose members have been high‐level government officials or members of Congress, suggested that an interagency group is essential for effective cooperation among government agencies in responding to events. They are highly experienced people, and what they suggest is likely to be right. But they may not appreciate the psychological shifts in people, the rearrangements of values and goals, when their primary responsibility is to some other work and to colleagues and officials who do other work, and the prevention of genocide and mass atrocities is at most a secondary responsibility. This consideration suggests that, as I suggest above (and for a more extensive discussion, see Staub 2011), there should also be an independent separate office, as well as an interagency group that includes members of this office. Effective prevention is more likely if responsible officials in different countries work in coordination with each other, the UN, relevant NGOs, and other agencies in their governments.

The Holocaust Museum, United States Institute for Peace (USIP), and other institutions currently train varied professionals and help develop knowledge in this area. International Centers for the Prevention of Genocide, proposed by David Hamburg (2007), are other institutions where knowledge can be further developed and where extensive training of leaders/government officials and practitioners in genocide prevention can take place.

For a system that effectively promotes preventive actions to be created, and for governments to respond to events in faraway places, citizen action is important. The large citizen movement in response to the violence in Darfur was likely to have had a role in the International Criminal Court's indictment of the president of Sudan for crimes against humanity in February 2009. While there were immediate negative actions by the Sudanese government in response, contrary to what was feared, by late in 2009 the violence in Darfur nearly came to a halt. Unfortunately, in 2011, there is new violence by Sudan—for example, in the Nuba Mountains in the state of Southern Kordafan. Clearly, in a constantly changing world, an indictment by itself is not enough.

Through public education and constructive groups, citizens can come to see both the importance of preventing mass violence and their role in bringing this about. When citizens demand it, leaders will create the institutions that can move them, the leaders and their countries, to action in response to crises and bring about early prevention as a systematic, ongoing enterprise.

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