Can some acts of violence be explained by a society's "culture"? Scholars have found it hard to empirically disentangle the effects of culture, legal institutions, and poverty in driving violence. We address this problem by exploiting a natural experiment offered by the presence of thousands of...

In the past decade, nearly 20 studies have found a strong, persistent pattern in surveys and behavioral experiments from over 40 countries: individual exposure to war violence tends to increase social cooperation at the local level, including community participation and prosocial behavior. Thus...