Realistic Group Conflict Theory
Working on the principle that the environment in which groups or individuals find themselves influences the likelihood of hostility or prejudice, Sherif (1966) proposed the theory of realistic group conflict (RGCT).
He stated that conflict between groups comes out of a conflict of interests. In other words, when two groups both want the same thing but only one can have it there will be competition and hostility between the groups.
Sherif's famous Robber's Cave experiment was a large scale field experiment in which he set up a situation where two groups of boys were put into competition for resources. The hostility that this competition elicited even surprised the experimenters.
Click here to read more about Sherif’s Robber’s Cave Experiment.