Conflict has been shown to have large and long lasting impacts on ethnic groups. We examine the origin of this effect in social capital depreciation when past conflict experience aggravates anti-social behaviour. We conducted a money-burning field experiment to examine how the 1976–2005 conflict in Aceh, Indonesia affects current interactions between the ethnic groups involved. In addition to ethnic outgroup effects, we find that females who experienced the conflict burn their co-participants more than males.