A new Journal of Economic Growth study by Lena Gerling and Arzu Kibris uses Turkey’s conscription system and its long-running civil conflict as a natural experiment to study how battlefield exposure changes trust. The core finding is stark: men exposed to armed conflict during military service became more trusting of their ingroup, but not more trusting of outsiders or people in general.

The study finds that battlefield trauma lowers trust overall, while conflict exposure is associated with stronger ingroup-biased attitudes, including nationalism, intolerance, religiosity, and conformity to social norms. The authors conclude that conflict exposure does not build broad social capital, but shifts social preferences toward ingroup favouritism, a pattern they argue can damage long-run economic development and institutional quality.

“Our empirical findings indicate that those men who had served in high conflict intensity locations during their conscription service exhibit higher levels of trust in social ingroups like family members, friends, neighbours, and townsmen, as well as in Armed Forces which, given that they were once members of it, can be considered as another ingroup for them.
We, however, do not observe any significant effect on outgroup or generalized social trust or trust in any other state institution. Also importantly, we find traumatic combat experiences to reduce trust in all social and institutional groups we analyse. Investigating potential mechanisms, we observe that serving in a conflict zone induces a more general increase in
ingroup-biased social attitudes like nationalism, intolerance, religiosity and norm adherence. In other words, our results indicate elevated ingroup favouritism among exposed veterans.”

Abstract:

This study examines how exposure to armed conflict affects group-specific trust, focusing on individuals exposed during military service. Our identification strategy exploits a population-level natural experiment generated by Turkey’s strict military conscription system and its long-running civil conflict. We combine this setting with an original field survey to identify causal effects and examine individual-level mechanisms while minimizing contextual confounding. We find that men exposed to the armed conflict during their conscription service exhibit elevated ingroup trust, with no corresponding increase in trust toward outgroups or in generalized trust. In contrast, those with battlefield traumas display lower trust overall. Exposed veterans also display stronger ingroup-biased attitudes like nationalism, intolerance, religiosity, and adherence to social norms. These results suggest that conflict exposure shifts social preferences toward ingroup favouritism without strengthening broader forms of trust, a pattern that is likely to hinder the accumulation of social capital and, in turn, adversely affect long-run economic development and institutional quality.

The entire study is available through the following link.