Social Judgment Theory Experiment was conducted by Henry Tajfel along with his colleagues. This experiment was designed to explore the internal processes of an individual's judgment, how little it takes for people to form into groups, and the degree to which people within a group tend to favour the in-group and discriminate the out-group.
Man is a social being. This is one of the very basic concepts in the field of Social Psychology. This same concept entails that man has an inherent desire to socialize and mingle with other men. A consequence of this interaction between individuals is the tendency to bunch together in groups, may it be completely inclusive of all individuals or highly exclusive and limited to a select few.
Once we are a part of a group, we tend to do unexpected things like copying or adapting the attitudes and images of the other members, find our place in the social hierarchy and our individual role in the group, favour the in-group and look for a suitable leader within the group.
We can also differentiate the types of groups that we are a member of depending on the degree and the depth of our membership.
First, consider a group of old professionals who have known each other since childhood, or men within a fraternity, or a military unit. We can expect these groups to be long-lasting and the attitudes that the members share are time-enduring.
Compare this to a group such as a school math club, a group of passengers riding the same bus, or a group of golf players competing in a tournament. The later set of examples can be considered as transient groups since the degree and depth of membership is miniscule when compared to the first set of examples.
Social Identity Experiment
A sample of 48 boys, 14-15 years old, was initially divided into three groups of 16 boys each. Each group was shown 12 slides portraying different painting. One half of the paintings were by Kandinsky and the other half were painted by Klee. All the boys viewed the paintings without the signatures of the painter. After the exposition of the paintings, the boys were asked to express their preferences, which paintings did they like and which paintings did they hate. Please keep in mind that the boys were not aware of the painters of the pieces that they said were good or not.
After this initial stage of the experiment, the boys were seemingly allocated to two separate groups. They were given the impression that this grouping was based on the impressions that the experimenters received from them after the initial part of the experiment. The two groups were named Kandinsky group and Klee group. The names that were given to the group added up to the impression that the groupings were based on the expressed preferences of the boys but the truth is, the grouping was completely randomized.
The last stage of the experiment is the rewards allocation task. Each boy was given a task to award points to two other boys, one from his same group and one from the other group. The only information that each boy was given were code numbers and the name of the group of the two boys they were supposed to award. There were two systems of awarding points that were employed by the researchers.
First, the point scores for each boy were tied together, so that the sum of the two scores is 15. In this system of point awarding, when a participant chose a score (x) for one boy, the other boy automatically got a score (15 - x). This means that as the score for the initial boy increases or approaches 15, the score of the other boy decreases or approaches 0.
Klee Group Member 12
Kandinsky Group Member 6
In the second method of allocating points, Tajfel manipulated the grids so that the maximum number of points the boys could give to their in-group meant that the out-group automatically gets more points.
If a Klee member chose 19 for another Klee member, it would give the maximum points for the in-group but it would also give a higher profit to the out-group. (Maximum in-group profit)
If a Klee member chose 13 for another Klee member, it would give the same points for the other group. (Maximum equality or fairness)
If a Klee member chose 17 for another Klee member, it would give the highest possible profit to the other group (25) ensuring that the maximum cumulative number of points is given to the two groups. (Maximum joint profit)
If a Klee member chose 7 for another Klee member, it would give the least number of points to the other team (1). (Maximum profit difference favouring the in-group)
Klee Group Member 12
Kandinsky Group Member 6
In the first system of point awarding, the boys generally awarded more points to the members of their in-group showing in-group favouritism. In the second system of point awarding, the boys generally opted to maximize the difference between the profits of the two groups favouring their in-group.
One of the most obvious conclusions that we can draw from this experiment is the natural tendency of members of a group to favour their in-group. Despite the seemingly meaningless groupings created by the experimenters, the subjects were able to identify with their respective groups and create a positive social identity through giving their in-group more points.
This phenomenon can be likened to "self-serving bias." Since every individual within a group was able to identify themselves with their group, the group is now associated with one's self, thus, benefit of the group identified with the self is prioritized.
Completely related to this study is a follow-up research done by Tajfel and Billig in the year 1973. In this study, they showed that even if the members of the groups were aware that grouping was completely randomized and not based on the subject's expressed preferences, the participants still showed in-group favouritism.