Tajfel H., (1970)
Experiments in Intergroup Discrimination
Aim: to demonstrate that merely putting people into groups (categorisation) is sufficient for people to discriminate in favour of their own group and against members of the other group.
The subjects were 64 boys, 14 and 15 years old from a comprehensive school in a suburb of Bristol.
The subjects came to the laboratory in separate groups of 8. All of the boys in each of the groups were from the same house in the same form at the school, so that they knew each other well before the experiment. The first part of the experiment served to establish an intergroup categorisation. At first the boys were brought together in a lecture room and were told that the experimenters were interested in the study of visual judgements. Forty clusters of varying numbers of dots were flashed on a screen and the boys were asked to record each estimate in succession on prepared score sheets. There were two conditions in the first part of the experiment. In one condition, after the boys had completed their estimates they were told that in judgements of this kind some people consistently overestimate the number of dots and some consistently underestimate the number, but that these tendencies are in no way related to accuracy. (‘under-estimators - over-estimators’ condition). In the other condition the boys were told that some people are consistently more accurate than others. (‘better’ - ‘worse’ condition). Four groups of 8 served in each of the two conditions. After the judgements had been made and scored by the experimenter the boys were told that they were going to be grouped on the basis of the visual judgements they had just made. The subjects were actually assigned to groups at random. The second part of the experiment aimed to assess the effects of categorisation on intergroup behaviour. The subjects were taken to separate cubicles and told which group they were in. The students were given a booklet of...