Social Identity Theory is a concept in sociology that explains how a person’s sense of self and identity is shaped by the groups they belong to. This theory was first introduced by Henri Tajfel in the 1970s and has since been developed and expanded upon by other researchers in the field.

What is Social Identity?

Social identity refers to the part of a person’s self-concept that comes from their membership in various social groups. These groups can be based on anything from race, gender, religion, nationality, or even something as simple as liking a certain sports team. According to Social Identity Theory, people tend to categorize themselves into these groups and then compare themselves with others who belong to different groups.

How Does Social Identity Affect Behavior?

Once someone identifies with a particular group, they often start to adopt the norms and values of that group. This can lead to behaviors that align with those of their group members even if those behaviors are not necessarily aligned with their personal beliefs or values.

For example, if someone belongs to a political party that supports a particular policy, they are more likely to adopt that policy regardless of whether it aligns with their personal beliefs or not. This is because they want to maintain their sense of belonging within the group.

Social Comparison

The concept of social comparison plays an important role in Social Identity Theory. This theory suggests that people tend to compare themselves with others who belong to different social groups. They will often view their own group as superior or “better” than other groups.

This type of comparison can lead to prejudice and discrimination against members of other groups. For instance, if someone belongs to a racial group that is viewed as superior, they may have negative attitudes towards people who belong to other races.

In-Group Bias

Another important aspect of Social Identity Theory is in-group bias. This refers to the tendency of people to favor members of their own group over members of other groups. This can lead to a variety of behaviors, such as providing more resources or opportunities to members of their own group or treating members of other groups unfairly.


Social Identity Theory plays an important role in understanding how humans interact with each other. By recognizing the impact that social groups have on our sense of identity and behavior, we can work towards creating a more inclusive and equitable society.