In the summer of 1954, 22 young boys were invited to spend some time at a summer camp. The site was to be an isolated, densely wooded stretch in the Sans Bois mountains, in southeastern Oklahoma, where two cabins—far enough apart that they were beyond seeing or hearing distance of one another—would be put at the boys’ disposal. Each cabin would have its own separate swimming, boating, and camping areas, and there would be plenty of space for those quintessential camp activities that form the backbone of an eleven-year-old’s camp memories.

The boys themselves were all well-adjusted fifth graders, scheduled to start the sixth grade that fall. The eldest among them—one of them, to be precise—was all of twelve years old; the youngest, just short of eleven. Their backgrounds were of a kind: all came from established, middle-class Protestant families. All had been doing above average work in their respective schools. All were of above-average IQ.

But when they reached the camp, they didn’t all head in the same direction. Instead, they had been pre-arranged into two wholly separate groups, headed for those two wholly separate cabins and camping areas. In fact, as far as the arriving youngsters were concerned, there were only eleven of them to begin with; they were completely unaware of the existence of a mirror group on the other end of the campground.

The groups themselves were highly similar. They’d been previously matched as closely possible for things like height and weight, athleticism and popularity outside of camp, previous camp experience and musicality, and so on. To an outside eye, they were just your typical kids arriving for a relaxing stay at summer camp.

In reality, they were no such thing. They were instead the subjects in what has since become one of the most famous studies in social psychology—specifically, the area devoted to intergroup relations: Muzafer Sherif’s Robbers Cave experiment. The goal of the study was multifold: to see how quickly group identity could become established among strangers, how fixed or flexible that identity was, how it would play out in competitive settings with other groups, and how the group conflict dynamic could be mitigated after the fact.

The experiment itself was carried out in three parts. First, the two groups were allowed to bond, in isolation from one another. They were assigned activities that held a common appeal for group members and that depended on the collective effort of the group as a whole (such as a treasure hunt with a $10 reward that the group could spend as it wanted to).

After seven to eight days, what had at the onset been two amorphous clusters became organized, hierarchical units, with established leaders, easily identifiable high- and low-status members, and established norms of behavior—that were not to be violated if one didn’t want to incur the wrath of the others. The groups even chose names for themselves: the Rattlers and the Eagles.

What’s more, in the last days of this early phase, each group had glimpsed the other ever so briefly. There’d been no direct interaction, but the little they saw didn’t stop the boys from developing a quick antipathy to their perceived rivals. It wasn’t long before an “us” versus the “outsiders” or “intruders” rhetoric developed among the campers—and one group even claimed the single baseball diamond for itself, by staking a flag on the mound to protect “our” field. Both sides began to demand a chance to face off against the other and prove their superiority once and for all.

It was time for stage two: the moment of more direct competition and frustration. The camp’s staff—in reality, participant observers—announced that, in response to the boys’ demands, there would be a tournament between the two groups. It would consist of such activities as baseball, tug of war, touch football, and tent pitching. At the end, there would be a scavenger hunt. And if the stakes weren’t high enough as they were, the counselors offered further incentive: the winners would receive a trophy (an impressive trophy exhibit was promptly displayed in the dining hall) and prizes of knives and medals.

Then came the first actual meeting, when the Rattlers and Eagles were brought face to face on the baseball diamond for the first time. It didn’t take long for the initial antipathy to devolve into nasty name-calling. “Dirty shirt!” one boy screamed at the start (a phrase I initially misread as somewhat more colorful), and others soon took up the game.

As it happens, that name-calling was the least of what was to take place. The relations between the Rattlers and the Eagles degenerated rapidly. The Eagles burned the flag that the Rattlers had so proudly erected on the baseball diamond. The Rattlers retaliated by burning the Eagles’ own flag. The Eagles, in turn, tore up the Rattlers’ second flag. This time, the Rattlers hit back with a nocturnal raid on the Eagles’ cabin, in “commando style.” They turned over beds, ripped mosquito netting, stole one boy’s jeans and a stack of comic books.

The Eagles were none too pleased. When the Rattlers were eating dinner, they returned the raid—but this time, they upped the ante, bringing with them sticks and bats to wreak maximum havoc. They then filled their socks with stones to use as weapons, on the chance that the Rattlers would soon plan a counter-raid of their own. (The rocks, in case you’re wondering, were never used; the counselors, who for the most part looked on in silence, intervened on that front.)

At the end, the Eagles won the tournament. But during their triumphant celebration, the Rattlers struck back, at raid and defeat both: they again invaded the Eagles’ cabin—and proceeded to not only wreck the place, but steal the prize knives and medals.

The two sides then met for a fight. (I picture here a Westside-Story-type rumble in the making.) But before it could get as rough as the boys had been planning, the staff once again stepped in, pulling the offenders back and forcing both sides to withdraw. It was a psychology experiment, after all, not a gang.

Stage two had concluded successfully. Now, it was time for the final part: could the experimenters succeed in reducing the friction that had risen to such great—and violent—heights?

First, they tried out the “mere contact” theory: that simply letting the two groups interact on an equal footing would, over time, repair the breach. No such luck. Though outings were planned, movies watched, meals served at the same time, the Rattlers and the Eagles refused to associate. The closest they came to interacting was throwing food and papers—in equal proportion to flying epithets—at one another in the dining hall.

Clearly, a more forceful approach was needed. So, the researchers moved to another tactic. Would the groups start getting along if they had a common superordinate goal?

A number of elaborate set-ups followed. In the first, the camp’s drinking water was artificially blocked—and as the campers’ thirst rose apace, they began to work together, at the counselors’ behest, to identify the problem. For a time, they were on the same team. All seemed according to plan. But once the problem had been resolved, the behavior once more degenerated—and that evening, another food fight erupted over dinner.

With each successive task, however—paying for a movie (“Treasure Island”) that everyone wanted to see, restarting a stalled food truck during a joint camp-out, preparing food during that same camp-out, pitching tents with missing supplies, and so forth—the antagonism showed signs of mellowing. By the end of that final camping trip, the Rattlers even went so far as to share $5 they had won in a bean toss with the Eagles, to buy malts for both groups.

Sherif concludes on an optimistic note: perhaps the same tools used to bring the boys back together can help in intergroup conflict on a broader scale. He writes,

Tools and techniques can be put to the service of harmony and integration as well as of deadly competition and conflict. Tools, in themselves, are not opposed to cooperation among individuals using them. It is the individuals as group members who put the tool to use in their opposition to other groups.

Alas, it’s easier to bring together eleven-year-old boys in a camp, who have everything in common save for an arbitrary group designation. It’s tougher to do so in the real world. Subsequent studies have shown just how easily groups are formed, on the most arbitrary of bases (more on that in my next piece)—and how hard they can be to unform. As the stakes rise, as the diversity increases, as the group identification becomes based on something more than a random division into cabins, so too does the difficulty of unraveling the enmity increase.

Even in the Robbers Cave, consider how quickly the animosity arose—and over how long a period of time (and through how much greater effort) it was eventually (though never quite altogether – some boys persisted in the divisions) extinguished. And that, despite the fact that the conditions for resolution were ideal: a captive audience, the ability to orchestrate unifying situations over and over. And when the study is recounted today, more often than not the focus is on the violence instead of its resolution, on how nasty boys can become in how short a period of time—and how persistent that nastiness can be.

Groups form easier than they fall apart—and they have many an impetus to form on their own, without so much as a hint at experimental manipulation. Over and over, the effects of the process play out in things as weighty as those Sherif mentions, like international conflict, and as comparatively minor as how we approach literature.

Part of me wonders: how are the Robbers Cave boys faring today? When they look back on their summer, what do they recall, the competition and nastiness or the reconciliation? Have they stayed in touch—and do they ever think back on themselves as Eagles or Rattlers? Did the experience give them any insight into themselves, insight that they might later apply to being a little less quick to judge, to name, to antagonize—or was Robbers Cave just a summer, like any other?

All images taken from Sherif et al's 1954/1961 book, "Intergroup Conflict and Cooperation: The Robbers Cave Experiment"

Sherif, M. (1954). Status in Experimentally Produced Groups American Journal of Sociology DOI: 10.1086/221569