Based on this research, Tajfel first defined the concept of social identity in 1972. The concept of social identity was created as a way to conceptualize self based on a social group to which a person belongs. Then, Tajfel and his student John Turner introduced the theory of social identity in 1979. The theory aims to illuminate the cognitive processes that lead people to define their group membership and the motivational process of enabling people to maintain positive social identity by beneficially comparing their social groups. To other groups. The social identity theory stipulates three psychological processes for individuals to perform intra-group/out-group classification. The first process, social classification, is the process by which we organize individuals into social groups to understand our social world. This process allows us to define people based on the group we belong to, including ourselves. We tend to define people based on their social category, not their personal characteristics.