Ethnic hostilities often spread rapidly. This paper investigates the influence of peers on willingness to sacrifice one’s own resources in order to cause harm to others. We implement a novel experimental design, in which we manipulate the identity of a victim as well as the social context, by allowing subjects to observe randomly assigned peers.
The results show that the susceptibility to follow destructive peer behavior is great when harm is caused to members of the Roma minority, but small when it impacts co-ethnics. If not exposed to destructive peers, subjects do not discriminate. We observe very similar patterns in a norms elicitation experiment: destructive behavior towards Roma is not generally rated as more socially appropriate than when directed at co-ethnics but norms are more sensitive to social contexts. The findings can help to explain why ethnic hostilities can spread quickly among masses, even in societies with few visible signs of systematic inter-ethnic hatred, and why many societies institute hate crime laws.