Give two rival boy gangs a shared crisis, and the rivalry dissolves

In 1954, researchers split 22 boys into two camp groups that turned hostile within days of competing for prizes — raiding cabins, burning flags. Talking it out didn't help. Only tasks that forced both groups to cooperate, like fixing a 'broken' water supply together, dissolved the hostility.

— Muzafer Sherif, O.J. Harvey, B. Jack White, William Hood, Carolyn Sherif, Intergroup Conflict and Cooperation: The Robbers Cave Experiment — University Book Exchange, Norman OK, 1961 (basis of Realistic Conflict Theory)
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