"Warfare leaves terrible legacies, from raw physical destruction to shattered lives and families. International development researchers and policymakers sometimes describe war as “development in reverse”, causing persistent adverse effects on all factors relevant for development: physical, human, and social capital. Yet a long history of scholarship from diverse disciplines offers a different perspective on one of the legacies of war. Historians and anthropologists have noted how, in some instances, war fostered societal transitions from chiefdoms to states and further strengthened existing states. Meanwhile, both economists and evolutionary biologists, in examining the long-run processes of institution-building, have also argued that war has spurred the emergence of more complex forms of social organization, potentially by altering people’s psychology. In this article, we discuss and synthesize a rapidly growing body of research based on a wealth of new data from which a consistent finding has emerged: people exposed to war violence tend to behave more cooperatively after war. We show the range of cases where this holds true and persists, even many years after war."The evidence on the after-effects of war on cooperation typically involves a survey component, in which people from a conflict-riven places like Sierra Leone, Uganda, Bosnia, Kosovo, and others are surveyed about the experience of their family in the war. For example, they might be asked questions like: "Were any members of your household killed during the conflict? Were any members injured or maimed during the conflict? Were any members made refugees during the war?" I
Evidence on social cooperation is then gathered in two forms. One is through additional survey data: that is, asking people about whether they now belong to clubs, vote, have an interest in politics, are active participants or leaders in community life, make voluntary contributions to public projects, and so on. The other is to have people participate in experimental games that seek to elicit attitudes toward cooperation.
Economists will be familiar with these games, like the ultimatum game, public goods game, and the like. Here are a couple of examples. the "dictator game" is one of the simplest of these games, in which one subject is given an amount to divide with another player. That's it! The player who is the "dictator" can keep it all, or give it all, and the amount they give can be viewed as a measure of likelihood to cooperation. In the more complex "trust game," the first player is given an amount to divide with another player. Whatever they give to that other player is multiplied by three. Then the second player gets to decide how much--if any--to return to the first player. When trust is higher, the first player will give more to the second player, in the hope or expectation of getting even more back.
The authors review 20 studies, and find that those who have been most exposed to the violence of war are more likely to show cooperative behaviors for years afterward. These effects seem especially strong when they are involved with players who in some way can be identified as members of their own group. I'll let you read the more detailed evidence for yourself, but it's perhaps worth noting one issue for any social science study. Is there some reason to believe that those who were more cooperative to begin with might also be more likely to suffer violence during wartime? The authors are fully aware of this argument,and write:
"For instance, more cooperative people might be more likely to participate in collective action, including civil defense forces or armed organizations that represent their groups during wartime, and thus more likely to live in a family that experiences some form of direct war victimization. Or perhaps attackers systematically target people who are likely to be more cooperative in nature, such as leading families or wealthy and influential citizens. If true, statistical tests would overstate the effect of war victimization on later civic participation and social capital. Attrition poses another potential challenge for causal identification if the least prosocial or cooperative people are also more likely to die, migrate, or be displaced and not return home."
The short answer to these concerns is that n many of these conflicts, it is frighteningly plausible that these direct experiences of violence were more-or-less randomly distributed across certain villages or populations. Thus, it is plausible that their higher cooperation is an after-effect of having experienced violence.
One intriguing question asked near the end of the paper is whether the effect of war-time violence on cooperation might also arise after other types of violence. The authors write (citations omitted):
"Another important direction is to examine other forms of physical insecurity, including crime, state repression, natural disaster, life-threatening accidents, and domestic abuse. In particular, the distinction between wartime violence and urban crime may not be large in certain cases, especially where widespread organized crime takes on characteristics of civil conflict, such as the cases of Mexican or Colombian drug trafficking organizations. Early evidence does indeed suggest that our findings on violence and cooperation could generalize to a wider range of situations. The meta-analysis finds that those who have experienced crime-related violence are also more likely to display cooperative behavior, just like war victims. There are parallels in related literatures, including findings that victims of crime are more likely to participate in community and political meetings, be interested in politics, and engage in group leadership. Other emerging evidence exploring the effects of post-election violence, and earthquake and tsunami damage also mimics the main finding of this paper, namely that survival threats tend to enhance local cooperation."Of course, neither the authors nor anyone else is arguing that the costs of war and violence are offset by a modest if real improvement in cooperation. But as one considers the grim violence that stalks the lives of so many people around the world, any possible glimmer of light for the aftermath is welcome.
(Full disclosure: I'm the Managing Editor of JEP, and have been in that role since 1986. Since 2011, all JEP articles are freely available on-line compliments of the American Economic Association.)