Cognitive and neural bases of collateral damage during intergroup conflict

Civilian casualties occur during military attacks. Such collateral damage is prohibited by international laws but increases with substantial consequences when intergroup conflict escalates. We investigate cognitive and neural bases of collateral damage by integrating brain imaging and statistical modeling of punishment decision-making during intergroup conflict. We test two Chinese groups manipulated in a laboratory setting and two ethnic groups (Israeli-Jews and Arab-Palestinians) in Israel. The results dissociate two psychological constructs, i.e., harm preference and harm avoidance, which respectively characterize punishment decision-making related to outgroup combatants and noncombatants during intergroup conflict. In particular, individuals show decreased avoidance of harming outgroup noncombatants when conflict escalates. Moreover, the decreased harm avoidance is predicted by inhibition of the left middle frontal activity during the selection of punishment decisions. Our findings provide a new perspective on the cognitive and neural bases of collateral damage and have important implications for understanding civilian casualties during the war.