In 1954, psychologists Muzafer Sherif and Carolyn Wood Sherif brought two groups of eleven- and twelve-year-old boys to Robber’s Cave, a summer camp in Oklahoma. Each group occupied a different part of the camp and, for five days, thought itself alone. Each marked out its territory and chose a name - the ‘Eagles’ and the ‘Rattlers’ - and each became a tribe.
On day six, the Sherifs arranged for each tribe to become aware of the other. They also created artificial situations that were zero-sum. In games between the tribes, there were prizes such as a medal and a multi-bladed pocket knife for the winners, but no consolation prizes for the losers. The psychologists also found other ways for one tribe to gain at the expense of the other, like delaying one group reaching a picnic to find that the others had eaten all their food.
Antagonism was instant. Each group became still more tribal - making flags, hanging them in disputed territory, and raiding each other’s bases. The groups became so aggressive with each other that the researchers had to separate them physically.
