Did you ever wonder, when you were a kid, whether your inane "summer camp" actually had some kind of elaborate hidden purpose—say, it was all a science experiment and the "camp counselors" were really researchers observing your behavior?

Me neither.

But we'd have been more paranoid if we'd read Intergroup Conflict and Cooperation: The Robbers Cave Experiment by Sherif, Harvey, White, Hood, and Sherif (1954/1961). In this study, the experimental subjects—excuse me, "campers"—were 22 boys between 5th and 6th grade, selected from 22 different schools in Oklahoma City, of stable middle-class Protestant families, doing well in school, median IQ 112. They were as well-adjusted and as similar to each other as the researchers could manage.

The experiment, conducted in the bewildered aftermath of World War II, was meant to investigate the causes—and possible remedies—of intergroup conflict. How would they spark an intergroup conflict to investigate? Well, the 22 boys were divided into two groups of 11 campers, and—

—and that turned out to be quite sufficient.

The researchers' original plans called for the experiment to be conducted in three stages. In Stage 1, each group of campers would settle in, unaware of the other group's existence. Toward the end of Stage 1, the groups would gradually be made aware of each other. In Stage 2, a set of contests and prize competitions would set the two groups at odds.

They needn't have bothered with Stage 2. There was hostility almost from the moment each group became aware of the other group's existence: They were using our campground, our baseball diamond. On their first meeting, the two groups began hurling insults. They named themselves the Rattlers and the Eagles (they hadn't needed names when they were the only group on the campground).

When the contests and prizes were announced, in accordance with pre-established experimental procedure, the intergroup rivalry rose to a fever pitch. Good sportsmanship in the contests was evident for the first two days but rapidly disintegrated.

The Eagles stole the Rattlers' flag and burned it. Rattlers raided the Eagles' cabin and stole the blue jeans of the group leader, which they painted orange and carried as a flag the next day, inscribed with the legend "The Last of the Eagles". The Eagles launched a retaliatory raid on the Rattlers, turning over beds, scattering dirt. Then they returned to their cabin where they entrenched and prepared weapons (socks filled with rocks) in case of a return raid. After the Eagles won the last contest planned for Stage 2, the Rattlers raided their cabin and stole the prizes. This developed into a fistfight that the staff had to shut down for fear of injury. The Eagles, retelling the tale among themselves, turned the whole affair into a magnificent victory—they'd chased the Rattlers "over halfway back to their cabin" (they hadn't).

Each group developed a negative stereotype of Them and a contrasting positive stereotype of Us. The Rattlers swore heavily. The Eagles, after winning one game, concluded that the Eagles had won because of their prayers and the Rattlers had lost because they used cuss-words all the time. The Eagles decided to stop using cuss-words themselves. They also concluded that since the Rattlers swore all the time, it would be wiser not to talk to them. The Eagles developed an image of themselves as proper-and-moral; the Rattlers developed an image of themselves as rough-and-tough.

Group members held their noses when members of the other group passed.

In Stage 3, the researchers tried to reduce friction between the two groups.

Mere contact (being present without contesting) did not reduce friction between the two groups. Attending pleasant events together—for example, shooting off Fourth of July fireworks—did not reduce friction; instead it developed into a food fight.

Would you care to guess what did work?

(Spoiler space...)

The boys were informed that there might be a water shortage in the whole camp, due to mysterious trouble with the water system—possibly due to vandals. (The Outside Enemy, one of the oldest tricks in the book.)

The area between the camp and the reservoir would have to be inspected by four search details. (Initially, these search details were composed uniformly of members from each group.) All details would meet up at the water tank if nothing was found. As nothing was found, the groups met at the water tank and observed for themselves that no water was coming from the faucet. The two groups of boys discussed where the problem might lie, pounded the sides of the water tank, discovered a ladder to the top, verified that the water tank was full, and finally found the sack stuffed in the water faucet. All the boys gathered around the faucet to clear it. Suggestions from members of both groups were thrown at the problem and boys from both sides tried to implement them.

When the faucet was finally cleared, the Rattlers, who had canteens, did not object to the Eagles taking a first turn at the faucets (the Eagles didn't have canteens with them). No insults were hurled, not even the customary "Ladies first".

It wasn't the end of the rivalry. There was another food fight, with insults, the next morning. But a few more common tasks, requiring cooperation from both groups—e.g. restarting a stalled truck—did the job. At the end of the trip, the Rattlers used $5 won in a bean-toss contest to buy malts for all the boys in both groups.

The Robbers Cave Experiment illustrates the psychology of hunter-gatherer bands, echoed through time, as perfectly as any experiment ever devised by social science.

Any resemblance to modern politics is just your imagination.

(Sometimes I think humanity's second-greatest need is a supervillain. Maybe I'll go into that line of work after I finish my current job.)

Sherif, M., Harvey, O. J., White, B. J., Hood, W. R., & Sherif, C. W. 1954/1961. Study of positive and negative intergroup attitudes between experimentally produced groups: Robbers Cave study. University of Oklahoma.