War is hell and, according to new research, experiencing its horrors can cause people to have a greater affinity for members of their own group, particularly if they are exposed to warfare in later childhood or early adulthood.
“These effects have the potential to explain why conflict sometimes leads to cycles of war and sometimes stimulates nation‑building in its wake,” says study co‑author Joseph Henrich, a professor in UBC’s departments of Psychology and Economics.
The researchers collected data from 543 children in the Republic of Georgia following the brief but devastating war between Russia and Georgia over South Ossetia. They also collected data from 586 adults in Sierra Leone following an 11‑year civil war that ended in 2002, which led to the displacement of much of the population and the deaths of more than 50,000 civilians.
Based on evolutionary theory, the researchers hypothesized that experiences with intergroup conflicts should lead individuals to become more focused on their own group’s wellbeing, since individual survival is often linked to the fate of the group.
The subjects played games that involved choosing how to allocate tokens to themselves and an anonymous partner. In some cases, the anonymous partner was from the same village or school, and in other cases not. Those who had experienced war were more willing to sacrifice to reduce inequality if their partner was from the same village or school. No such effects were present in participants younger than six or older than 20 when they experienced war. “These findings suggest that if war is experienced during a sensitive window in development between middle childhood and early adulthood, then it leaves an enduring mark,” says co‑author Michal Bauer of Charles University, Czech Republic.
The research may help to explain why war can lead to nation building or a perpetual cycle of war. “When people identify with an in‑group that coincides with the state or nation, then nation‑building can be enhanced,” says Henrich. “For people who identify with a subnational identity, such as an ethnic group, war can sow the seeds of future conflicts.”