Oxytocin helps soldiers to like each other and hate the enemy

Soldiers form loyal groups fighting and dying for each other because they have the same instincts that cause mothers to ferociously protect their newborns, a study suggests. Researchers have found that in the heat of battle they have the same chemicals running through their bloodstreams as protective mothers, meaning they develop incredibly strong bonds with each other but become extremely aggressive to outsiders. The effect resolves around the hormone oxytocin which is released at times of stress and when people socialize with each other. But the scientists have found that this chemical, often referred to as the love or bonding hormone, also makes them – like mothers – incredibly aggressive to outsiders. Using a computer simulation game they found that volunteers given a spray of the hormone bonded more quickly and deeply with their own group but became much more hostile to outsiders. Oxytocin makes people kinder to their own groups but more aggressive to those outside.