Social Identity Theory

Henri Tajfel's greatest contribution to psychology was social identity theory.
Social identity is a person’s sense of who they are based on their group membership(s).

Tajfel proposed that the groups (e.g. social class, family, football team etc.) which people belonged to were an important source of pride and self-esteem.  Groups give us a sense of social identity: a sense of belonging to the social world.
In order to increase our self-image we enhance the status of the group to which we belong. For example, England is the best country in the world!  We can also increase our self-image by discriminating and being prejudice against the out group.
Therefore we divided the world into “them” and “us” based through a process of social categorization (i.e. we put people into social groups).
This is known as in-group (us) and out-group (them).  
Social identity theory states that the in-group will discriminate against the out-group to enhance their self-image.

The central hypothesis of social identity theory is that group members of an in-group will seek to find negative aspects of an out-group, thus enhancing their self-image.

Prejudice between cultures may result in racism; in its extreme forms, racism may result in genocide, such as occurred in Germany with the Jews, in Rwanda between the Hutus and Tutsis and, more recently, in the former Yugoslavia between the Bosnians and Serbs.

Henri Tajfel proposed that stereotyping (i.e. putting people into groups and categories) is based on a normal cognitive process: the tendency to group things together. In doing so we tend to exaggerate:

1. the differences between groups

2. the similarities of things in the same group.

We categorize people in the same way. We see the group to which we belong (the in-group) as being different from the others (the out-group), and members of the same group as being more similar than they are. Social categorization is one explanation for prejudice attitudes (i.e. “them” and “us” mentality) which leads to in-groups and out-groups.

A Class Divided provides me with a lot of concepts about the Social Identity Theory. First of all, the video is about a teacher who is experimenting a race discrimination with the kids of her room. throughout the experiment, the children eventually fight over what they are dominant, powerful over, and some kids start to cry. From these experiments, we can see that the theory of social Identity Theory effects very much in the social life of humans. For example, I noticed that there are examples in our school life also. In groups and Out groups have very categorized theories.
Since I am very big fan of Soccer, I will provide an exampe of a football ingroup and outgroup
It isn’t very often that, as an experimental psychologist, you get to see the thing that you study played out in real life in front of you – but that is what has happened to me today, watching the FA Cup football match between Liverpool and Manchester United.
For anyone unaware of the events leading up to this match, the Liverpool footballer Luis Suarez was found guilty by the Football Association of racially abusing the Man Utd footballer Patrice Evra in a match between the teams a few months ago. He was banned for eight maches after Evra complained that Suarez had called him things such as ‘Nigrito’, which Suarez admitted to but claimed it would not be considered racist in his home country of Uruguay.
Fast forward to the match today, with Evra playing and Suarez sat in the stands serving his ban. Every time Evra touched the ball a sizeable minority of Liverpool fans booed him. Why? Evra didn’t campaign for Suarez’s ban to be increased, he didn’t make hyperbolic statements on what happened – he merely reported what had happened. So why boo a player who is the victim of the situation?
It is very easy to say that the people who were booing are racist. It is equally easy for those booing to point out that they aren’t racist, as they didn’t boo other black Man Utd players such as Danny Wellbeck. This is where it gets interesting (and slightly more complicated) for researchers into prejudice, because there is an explanation that fits this model of behaviour very well – that of aversive racism.