The impact of armed conflict exposure on altruistic and parochial preferences

How does exposure to armed conflict shape altruistic behavior? We address this question by building on a natural experiment created by a military conscription system with an innovative study design that allows us to identify the causal effects and isolate individual-level mechanisms from broader societal changes. Measuring altruism and parochialism through a lab-in the-field experiment, we find conflict-exposed conscript veterans to display significant out-group derogation. A more detailed accounting of exposure shows the bias to concentrate among those with war traumas which, alongside out-group derogation, cause these individuals to display significant in-group favouritism, as well. Further analysis points to psychological mechanisms.