Social Identity Theory
What is Social Identity Theory?
Social identity theory is a psychological framework that explains how people build their sense of self and confidence from the groups they belong to. It shows how belonging to a group can lead to favoritism and contribute to stereotypes, bias, or unfair treatment toward those outside the group.
The Basic Idea
Think back to your first day in high school. You probably did not need a seating chart to figure out how the social landscape was already drawn. The athletes, the academics, the creatives, the gamers, the popular kids. The labels were not written down, yet they were easy to read. They shaped who you talked to, how you behaved, and most crucially, where you sat at lunch. Over time, your lunch table becomes part of how you understand yourself. You start to think like the group, act like them, and even laugh like them. And just as naturally, you become more aware of who does not sit there with you. Everyone else becomes “not us.” That unspoken boundary between “us” and “them” is where social identity theory comes to life.
At its core, the theory suggests that our identities are not formed in isolation, but rather, we define who we are partly through the groups we identify with. These might include nationality, religion, profession, political beliefs, or even something as trivial as your favorite band. Once we identify with a group, we tend to favor its members (the in-group) while viewing outsiders (the out-group) with increased skepticism. We begin to define ourselves not just by who we are, but by who we are not.
Social identity forms through three psychological stages. First, social categorization helps us make sense of the world by sorting ourselves and others into groups. Next, social identification occurs when we adopt the norms, values, and behaviors of our group. Finally, social comparison leads us to evaluate our group’s status against others. When our group is admired or successful, we feel better about ourselves. This dynamic can drive people to fiercely defend the group’s image, compete with rivals, or downplay internal flaws, all in the service of maintaining a positive self-image.
In the 1970s, social psychologist Henri Tajfel developed social identity theory to explain just how quickly group divisions can take hold. In one of his best-known experiments, participants were randomly assigned to groups based on trivial distinctions—for example, a coin toss or a preference for one abstract painting over another. Participants were then asked to allocate points or money to anonymous individuals, knowing only which group each recipient belonged to. Despite the meaningless distinctions, participants consistently demonstrated favoritism towards their own group and bias against the out-group. The results demonstrate how automatic and deeply ingrained our tendency to align with groups can be.
Social identity theory continues to shape how we understand human behavior. It sheds light on everything from school cliques to online echo chambers, brand loyalty, and politicized identities.
Without social identity, there is, in fact, no society.
― Richard Jenkins, author of Social Identity: Key Ideas in Sociology2
About the Author
Vivian Ching, PhD
Vivian Ching, PhD is an internationally acclaimed interdisciplinary strategist, educator, and artist whose work explores the intersection of behavioral science, creativity, and emerging technology. She holds five academic degrees from top institutions including the University of Virginia, University of Bath, and University of Warwick; and is a globally recognized artist with 19 exhibitions and over 80 media features, including Tatler, Cosmopolitan, and Harper’s Bazaar. In 2014, she became the first Chinese artist to send artwork into space—an experience that inspired her to explore art-tech integration in her book “AI for Creatives: Unlocking Expressive Digital Potential” with Taylor & Francis, which examines how AI is reshaping expression across the creative industries, from art and design to fashion and media.
