Intergroup conflict, also called civil conflict, is one of the world’s most serious problems, as warfare has shifted from the battlefield toward something enmeshed within civilian life. The constant exposure to high-stress conflict situations affects everyone, but it may have an outsized influence on developing adolescent brains. A recent study published in PNAS found that adolescents who grow up in protracted civil conflicts end up more empathetic and cognitively attuned to the people within their own group and less sensitive to pain felt by others.

The researchers who conducted this study recruited 85 adolescents from a conflict-ridden region in Israel. They categorized the participants as identifying either as Arab-Palestinian or Jewish-Israeli. The participants were shown a set of well-validated photographs of other people who clearly belonged to one of these groups, either in painful or non-painful conditions. During this task, each participant’s brain activity was measured using MEG (magnetoencephalography), a functional neuroimaging technique that tracks the magnetic effects of currents moving through neurons to visualize brain activity.

The authors found that adolescents from both groups (Arab and Jewish) responded differently to ingroup and outgroup images. All the subjects showed significant brain activation in pain-empathy regions when the pain images contained in-group characters. But when an outgroup figure was shown, there was no difference in the response, regardless of whether that figure was experiencing pain. So all participants could have an empathetic response, but only to members of their own group