Research conducted in Sierra Leone and Georgia has shown that people who live through the horrors of war develop strong in-group tendencies, particularly if experienced in middle childhood through early adulthood.
Children in both countries were asked to play a game where they had to split tokens between themselves and an anonymous partner. It was observed that they had a higher willingness to share if their partner was from the same village or school as opposed to a partner from a distant village.
"These 'war effects' emerge in the short-term and, importantly, they have long-term impact on psychology if war is experienced during middle childhood and adolescence,” said Joseph Henrich of the University of British Columbia.
The study observed 543 children in Georgia, six months after the devastating war between Russia and Georgia over South Ossetia. They also collected data from 586 adults in Sierra Leone following a 11-year civil war in the country.
Participants who experienced war were far more willing to sacrifice for a fellow villager. Interestingly, this trend was not observed in participants younger than six and older than 20.
"These findings suggest that if the war experience takes place during a sensitive window in development between middle childhood and early adulthood, then it leaves an enduring mark," said study co-author Bauer.
Henrich added that this explained why long-drawn conflicts were followed by strong nation-building sentiments.
When people identify with an in-group that coincides with the state or nation, then nation building can be enhanced," says Henrich. "This could help to explain America's 'Greatest Generation,' which emerged after World War II."