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Key Study: the Robber’s 
Cave Experiment

Muzafer Sherif, O J Harvey, Jack White, William Hood & Carolyn Wood Sherif 1954/1961

Updated: 15 January 2013



AIMS: Muzafer Sherif wanted to see if it was possible to instil prejudice between two very similar groups by using real life scenarios to develop group norms and values and then putting the 2 groups in competition with each other.

PROCEDURE (METHOD): In 1954 22 11-12-year-old boys took part in a 2-week summer camp at the 200-acre Boys Scouts of America camp completely surrounded by the 200-acre Robber’s Cave State Park in the western United States. (The ‘Robber’s Cave’ had been the hideaway of Jesse James.) The boys were screened to ensure they were well-adjusted - no neurotic tendencies and no record of past disturbances in behaviour - and came from a similar background - white, Protestant, stable two-parent families of the middle socioeconomic level in Oklahoma. None of the boys knew each other, coming from different schools and neighbourhoods. As part of the matching process, the boys were rated (including IQ) by teachers. The boys were assigned to one of 2 groups. The groups themselves were very similar. They were matched as closely possible on criteria such as height and weight, athleticism and popularity outside of camp, previous camp experience and musicality.  They were then, as individual groups, picked up by bus on successive days in the summer of 1954 and transported to Robber’s Cave.

The researchers acted as camp counsellors. A nominal fee was charged to parents for the camp; but they were asked not to visit on the pretext that it might make the boys homesick.

The research methods used were:-

Each group, initially unaware of the other’s presence, had their own cabin and were independent, camping out, cooking, improving swimming places, carrying canoes over rough terrain to water and playing various games. 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.

Each group soon developed a distinctive set of ideas and rules about how to behave. In one group it became the norm to act tough, swear a lot and not complain about small injuries. The other group swam in the nude and made any expression of homesickness taboo. Each group was tasked with coming up with a name for itself - thus, ‘Rattlers’ and ‘Eagles’ respectively - and a flag for their group. The researchers gave the 2 groups caps and t-shirts with their group names on to increase this sense of group identity. They became cohesive groups, with low-ranking and high-ranking members.

After a week the groups were made aware of each other. The researchers observed that in-group/out-group terms began to be used. When they watched a film together, they sat in their own distinct groups

The 2 groups wanted to play each other at baseball which enabled the researchers to introduce a competition: a grand tournament comprising 10 sporting events, plus cabin cleanliness awards and acting events. The boys were told that the best performing group in the tournament would receive a trophy, 4-bladed knives and medals. There were to be no prizes for the losers. The 2 groups were made to eat together in a common dining hall, where the tournament's grand prizes were on display for all to see.
The Rattlers' reaction to the informal announcement of a series of contests was absolute confidence in their victory! They spent the day talking about the contests and making improvements on the ball field,which they took over as their own to such an extent that they spoke of putting a ‘Keep Off’ sign there! They ended up putting their Rattler flag on the pitch. At this time, several Rattlers made threatening remarks about what they would do if anybody from The Eagles bothered their flag.

Even before the tournament began, the groups were insulting each other - eg: “Ladies, first” -  singing offensive songs about each other and refusing to ear together. They were even physical fights between members of the 2 groups! Soon epithets such as ‘sneaks’, ‘cheats’, bums’, ‘cowards’ and ‘stinkers’ were being used in reference to members of the other group. (Terms like ‘friendly’, ‘tough’ and ‘brave’ were used for their own group members.) The Rattlers, in particular, became concerned about encroachment on what they considered their territory - eg: “They had better not be in our swimming hole.”

The researchers manipulated the points so they could control the competition.When the Rattlers won a tug of war competition, the Eagles responded by burning their flag, with the group's leader proclaiming: “You can tell those guys I did it ... I'll fight 'em!” The Rattlers retaliated by raiding the Eagles camp (amid scuffles!) and damaging their property - overturning beds and ripping out mosquito netting. They stole one boy’s jeans and a stack of comic books. The Eagles were incensed. When the Rattlers were eating dinner, they returned the raid, 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 researchers intervened to calm things down.

With some ‘help’ from the researchers, the Eagles won - but their prizes, when awarded, were stolen by the Rattlers.

Now nearly at the end of the second week, the 2 sides met for a fight. However, the researchers again intervened, forcing both sides to withdraw.

The researchers mow instigated a 2-day cooling off period. In this time the boys were asked to list features of the 2 groups. The boys tended to characterise their own in-group in very favourable terms - eg: ‘friendly’, ‘tough’ and ‘brave’ - while the other, out-group  was characterised in very unfavourable terms such as ‘sneaky’, ‘bums’ and ‘cowards’.

Other evidence of in-group bias included, during the bean collecting task, members of one team consistently overestimating the numbers of beans collected by boys in their team and consistently underestimating the amount collected by the other team.

The researchers now realised they needed to reduce hostility between the 2 groups which they did by replacing the competitive goals with goals that could only be achieved by members of the two groups co-operating together.

First the researchers tried simply letting the 2 groups interact on an equal footing in the hope simply associating with each other would, over time, repair the breach. Though outings were planned, movies to be watched together and 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.

The researchers then arranged for the water supply to break down. (They turned off the valve and then placed 2 large boulders over it, blaming vandals for the problem.) First each group explored the 1.6 km pipeline separately; then they came together at the behest of the researchers and jointly located the source of the problem ( a clogged valve). When they restored the water supply, they cheered together. However, once the problem had been resolved, the behaviour degenerated again and that evening, another food fight erupted over dinner.

The next tactic was to tell the 2 groups that the camp could not afford to take them to see a film (‘Treasure Island’) most boys had high on their list of preferences. The two groups got together and worked out how they could get the money together jointly and see the film.

With each successive task, including preparing and pitching tents together, the antagonism showed signs of mellowing.

Finally the lorry due to transport their food on an outing to Cedar Lake some distance away wouldn’t start (by arrangement of the researchers) - so the boys got the tug-of-war rope and pulled together to get it to start.


FINDINGS (RESULTS): An in-group preference shown by the boys in each group increased substantially when explicit competition between them was introduced. The introduction of common objectives over a period of days reduced friction equally substantially.

The table on the next page shows how ‘out-group friendships’ increased via the collaborative activities.

(How well these ‘cooling down’ strategies worked was indicated that the boys chose to travel home on a single bus when offered the opportunity for the two groups to travel separately. When a stop was made for refreshments, one group used their last $5 prize money to buy malted milks for all the boys.)


CONCLUSIONS: Put into a group, the boys developed group identity with group norms, leadership and a status hierarchy.

Competition increased prejudice and discrimination, leading to clear inter-group conflict. Working together towards common goals led to much better relations and even something of a superordinate identity.


The first time the Rattlers and the Eagles saw each other...

Rattlers vs Eagles in tug of war contest...

The morning after the flag-burning incident the Eagles seize the Rattlers’ other flag!

Eagles raiding the Rattlers’ cabin!

Eagles and Rattlers working together to start the truck

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