• Sherif conducted a series of boys' summer camp experiments, one of which, known as the Robber's Cave Experiment, formed the basis of his realistic conflict theory. He found that if he introduced competition between boys in summer camp, Realistic Conflict Theory was created due to limited resources. Realistic group conflict is evident in society today.
  . For example, when a new group of immigrants arrive in a country, they can often be met with profound prejudice on the part of the indigenous population because they are viewed as competitors for resources such as jobs, housing and schooling.
  ¬ It results in extreme ingroup favouritism and solidarity and a marked hostility towards members of the outgroup.
  . However, when groups need to work together for a common aim (superordinate goal), there is a reduction in hostility and greater harmony between groups. Sherif believed that intergroup hostility could only be reduced by superordinate goals, where all members of each group need to cooperate in order to achieve the intended outcome.
• Earlier summer camp experiments involved similar aims to the Robber's Cave, to investigate the development of intergroup hostility in children. The Robber's Cave went on to investigate the reduction of prejudice. All three of these studies show how competition can give rise to intergroup conflict.

• The greatest amount of evidence for realistic conflict theory comes from Sherif's own field studies on intergroup conflict, including the Robber's Cave Experiment which found that competition increased hostility between the groups.
• These studies are further supported by anthropological studies, which found in tribal societies intergroup hostility increases where there is competition for resources and when populations expand and land becomes in short supply, conflict and violence increase.
  . Overall, these studies are important 'real-life' evidence for prejudice, giving the theory important ecological valid support.

However, Sherif criticised his own evidence.

• He found that evidence from his own writings about the experiments indicates that the groups of boys were becoming hostile towards each other even before the introduction of organised competitive events.
  . This suggests perhaps the presence of another group was sufficient to bring about prejudice (relating to social identity theory).

• An alternative explanation for prejudice comes from social identity theory. This theory proposes that the presence of perception of another group can lead to prejudice.
• Tajfel & Turner classified groups as either an in-group to which we have a membership or an out-group which is another rival group.
  . This suggests that group membership alone, even in the absence of competition, can cause prejudice.

• For a theory to be scientifically credible, it should be possible to demonstrate that the claims of the theory are wrong, this is known as falsification.
  . RCT produces testable hypotheses, e.g. 'levels of prejudice are greater before rival groups engage in a superordinate task than afterwards', this allows disproof. This shows RCT is a scientific theory, adding credibility to this explanation of prejudice and it claims about how prejudice might be reduced.

• Real-world evidence for realistic conflict theory comes from Aronson et al (1978) who introduced cooperation in the classroom where competition was rife.
  . Using the jigsaw technique, where students were divided into small groups that had to succeed in one group task to ensure the success of the overall class project, they found that levels of competition decreased. This demonstrates that the removal of competition decreases prejudice and increases liking between class members. This was similar to the final stage of Sherif's study where boys had to cooperate to fix a water supply or pull the camp bus out of a ditch together.