Social identity theory

Who are you?  This deceptively simple question can often be challenging to answer.  In fact, according to developmental psychologist Erik Erikson, developing a stable sense of identity is the major challenge facing teenagers.  If you are from a Western culture, you most likely define yourself by thinking of what makes you different, unique, and special from others.  But even so, much of your identity likely comes from the groups you belong to, and the people you identify with.  This is known as your social identity.
Try it Out

1.  Write a short personal introduction of yourself, in around 150-200 words, as if you were introducing yourself to an audience or completing the "About Me" section on a social media account

2.  Read my own personal introduction.  Try to count how many times social groups (for instance, nationality) are mentioned in this personal introduction. 

My name is Dan Barazani, and I'm a Secondary School teacher living in Thailand.  Born in Canada, I studied Psychology at McGill University and Education at the University of Toronto.  When not in the classroom, I enjoy travel, scuba diving, and photography.

3.  Read your personal introduction again.  How many social groups did  you mention in your personal introduction?
The Social Self

According to social identity theory, much of our sense of self comes from the groups we belong to.  For instance, in my own personal introduction, I catalogued a long list of groups that I identify with:  the nation of Canada, Psychology graduates, the profession of teachers, McGill and University of Toronto alumni, and so forth.  In fact, it would be very difficult (if not impossible) for me to define myself without mentioning any social groups.

Furthermore, people have a basic need for self-esteem.  In other words, we want to feel good about ourselves.  If a student comes to me after school and thanks me for being a great teacher, that will surely make my day.  We all want to feel like worthy, capable people that deserve respect and recognition from others.

Self-esteem sometimes comes from personal achievements.  If you score the winning goal that earns your sports team the championship, achieve a high grade on a really tough assignment, or help a friend through a difficult time, you'll probably feel really good about yourself.  But your self-esteem is also closely linked to your social identity - the achievements and success of your group.  If Canada were to win the Olympics in ice hockey, I'd feel great about being Canadian and joyous at our victory, even though of course I had nothing to do with the team's performance.  Simply belonging to highly regarded group gives my self-esteem a boost.  On the other hand, when people make disparaging jokes about Canada (perhaps about being too boring or just a poor backyard of the U.S.) my self-esteem will be a little wounded, even if they didn't intend it to be taken personally.

Based on the concepts of the social self and the need for self-esteem, psychologist Cialdini came up with an interesting prediction - that we'll closely identify with a particular social group when it is successful, but we'll put a little distance between ourselves and the social group when it fails.  For instance, if Canada were to win the Olympic gold medal for ice hockey, I'll be sure to proclaim my pride in being Canadian for all the world to hear, savouring the glory of being Canadian.  But if Canada were to be humiliated in a game of soccer (against, well, pretty much any country) I might keep my Canadian flags and T-shirts deep in the bottom of my closet, trying to avoid the embarrassment of the defeat.  Cialdini tested this idea with a simple yet brilliant field study on football fans in American universities.
Research: Cialdini

Aim:  Investigate the role of social identity in self esteem


  • This was a field study carried out on the campuses of 7 large American universities, which all had popular American football teams

  • Researchers recorded what clothing students were wearing the Monday after a big football match was played against a rival university

  • Researchers also called the students and asked them their opinion of their team's performance


  • Students were far more likely to wear clothing associated with their university (like a T-shirt with the school logo) if their university team won the football match

  • When asked to describe their team's performance, students were more likely to use first person pronouns (ex. "We played a great game")  if the team won, and more likely to use third person pronouns (ex. "They didn't play well as a team") if the team lost


  • Social identity (the groups you belong to) play an important role in self esteem 

  • To maintain a strong sense of self-esteem, people tend to closely associate themselves with a group when it is successful, and establish distance from a group when it fails


  • This study involved natural observation of real world behavior, so ecological validity is high

  • All participants were of a similar age (university students) and from the same culture (United States), so unclear of these results can be generalized to other age groups or cultures

  • Not clear if these findings apply to other types of groups as well - such as national or religious groups - or only to sports teams.  For example, if your country has a bad reputation for starting wars or violating human rights, will that cause you to identify with your country less?  More research is needed on this
Social identity theory

A Psychologist named Tajfel devoted his career to studying how social identifies are formed, and how they influence our behavior.  He developed social identity theory in 1979.  According to this theory, a number of cognitive processes are involved in belonging to a group:  categorization, identification, and social comparison.  To help you understand these processes, first watch a classic Canadian beer commercial called, "I am Canadian".

  • ​Categorization: Categorization is the process by which you group people together on the basis of certain characteristics - like their gender, age, nationality, religion, social group, occupation, and so forth.  Each category is like a box in your mind, and when you meet someone you immediately place them in a particular box.  For instance, while traveling, one of the most common questions that fellow tourists ask each other is, "Where are you from?"  By asking this question, we are immediately able to "place" someone in their proper category - like Canadian or American.  Furthermore, we often assume that people within a group all have certain characteristics in common - this is known as the "out-group homogeneity effect", and is closely related to stereotypes.  For instance, that all French people love wine and cheese, all Spanish people love salsa and take long siestas, and all Germans are efficient and boring.

  • Identification: Identification is when you categorize yourself as a member of a particular group, and take on the values and beliefs of that group.  For instance, in the commerical you watched, Joe takes on the identity of being Canadian, and embraces typical Canadian values - like respect for diversity, peacekeeping, and the nobility of the beaver.  In doing so, Joe also feels a special bond with other Canadians, who have all chosen to share the same set of values and beliefs.  In some cases, we tend to identify with certain groups almost by default - nearly everyone identifies with the gender and nationality they are born with, for example.  In other cases, identification with a group is a very conscious decision - for instance, if you join a fraternity, convert to a particular religion, or identify with your favorite brand of running shoes.

  • Social comparison:  Now that you've chosen to identify with a particular group, the final process of social identity theory involves comparing your group (the in-group) with other groups (out-groups).  As social identity is so important for self esteem, we are motivated to make comparisons that are favorable for our group whenever possible.  In other words, we look for ways to make our group seem better than the other group, perhaps by emphasizing our accomplishments and desirable qualities, and looking for deficiencies our rival groups.  For example, in the "I am Canadian" video, Joe implicitly compares Canada and the United States, suggesting that Canada is a far better place for embracing diversity (rather than assimilation) and peacekeeping (instead of policing), making it the "best part of North America".  The goal of social comparison is to establish positive distinctiveness for your group - that people in our group are unique and different from those in other groups, and that our group is the best (or at least as good as any of those other groups).

Tajfel believed that people have a tendency to identify with and fight for the interests of their groups - even when the groups are randomly assigned and devoid of any real meaning.  For example, in the British school system, students are divided into different-colored "Houses" for school competitions, and students are often fiercely competitive in achieving victory for their House.  Tajfel wanted to demonstrate that even the most trivial and meaningless groups tend to inspire in-group loyalty and competitiveness, and thus carried out experiments based on what he called the ​minimal group paradigm.

Research: Tajfel

Aim: Investigate how even minimal groups affects behavior


  • British schoolboys (aged 14-15) were randomly divided into groups.  In one experiment, they were divided into groups based on whether they overestimated or underestimated the number of dots on a picture, while in another, they were grouped based on whether they preferred the paintings of one artist or another

  • After playing a number of competitive games, the participants were given the opportunity to divide money (or points) to members of each group


  • Most boys gave more money (or points) to members of their own group, and less money to members of the other group

  • The majority of participants divided money (or points) between the groups in such a way as to maximize the difference between the groups.  In other words, many participants would accept less money for their own group if it meant that the other group would receive an even greater loss of money

  • Participants also rated their own group members as more likeable than the members of the other group


  • This study supports social identity theory.  People naturally categorize themselves into groups, identify with their own group, and seek to compare themselves favorable with opposing groups

  • This study suggests that even random, trivial and meaningless groups still have a significant effect on our behavior, resulting in loyalty to our group and hostility to the out-group


  • This study involved participants who were all British schoolboys aged 14-15.  Teenage boys are known to be quite competitive, so it is questionable whether the same results would be seen in girls, adult participants, or participants from other cultures

  • The study may have had demand characteristics - the boys may have felt the study was a competitive game to game the most money (or points) as possible, and hence acted accordingly

Evaluating SIT

Groups play a very significant role in influencing behavior.  In many cases, this can be positive - like when citizens of a country rally together to recover from a natural disaster, or when members of a religion organize fund raising activities to help less fortunate members of their community.  Other time, however, fierce loyalty to one's group can lead to many of the darker aspects of human behavior - wars, ethnic cleansing, even genocide.  To name just one example, during the worst periods of sectarian violence in Iraq (2006-2008), armed groups of Sunnis and Shias set up road checkpoints and executed people just because they belonged to the other sect of Islam.  Can social identity theory provide a convincing explanation of group behavior?  Here are some of the strengths and limitations of the theory:

  • SIT describes the cognitive processes (categorization, identification, and social comparison) that explain group loyalty and out-group hostility

  • SIT is supported by research, such as Cialdini's and Tajfel's studies

  • On the other hand, SIT does not completely explain why some group relations may involve friendly rivalry, while others descend into outright hostility and violence.  For example, although Canadians enjoy a healthy rivalry with Americans, most Canadian have generally positive feelings towards individual Americans and would certainly not kill someone just because they were American!

  • SIT explains inter-group rivalry in terms of the need for self-esteem and to feel your group is positive and distinctive.  While this may be true, there are undoubtedly other factors that influence group relations (such as competition for scare resources, or historical relations between the groups) which SIT does not address

Video Activity

  • Watch the video below on student cliques in a British secondary school

  • See if you can identify examples of categorization, identification, and social comparison

  • How do the students in this video try to establish positive distinctiveness ​for their group?

  • I can explain what is meant by the "social self", and the importance of the social self for self-identity and self-esteem

  • I can describe the processes involved in social identity theory:  categorization, identification, and social comparison, as well as the related concepts of the out-group homogeneity effect and positive distinctiveness

  • I can describe the Aim, Procedure, Findings and Conclusion of Cialdini's study on the importance of the social self for self-esteem, and can also evaluate the study

  • I can describe the Aim, Procedure, Findings and Conclusion of Tajfel's study on minimal groups, and can also evaluate the study

  • I can evaluate the strengths and limitations of social identity theory in explaining the behavior of people in groups
Quiz Yourself!

1.  What are two important functions of the social self?

(a) Positive distinctiveness and out-group homogeneity

(b) Identification and social comparison

(c) In-group favoritism and out-group hostility

(d) Identity and self-esteem

2.  Which of these findings was NOT observed in Cialdini's study?

(a) Men were more likely to wear team-affiliated clothing than women

(b) Students were more likely to wear university-affiliated clothing after a win

(c) Students referred to their team with first-person pronouns after a win

(d) Students referred to their team with third-person pronouns after a loss

3.  At "first year orientation" in a university, students might ask each other which high school they graduated from.  Which process in social identity theory is this most related to?

(a) Categorization

(b) Identification

(c) Social comparison

(d) Positive distinctiveness

4.  In Tajfel's minimal group experiments, how did most participants divide money (or points) between their team and other teams?

(a) They sought to maximise money (or points) for their own team

(b) They sought to minimize money (or points) for the other teams

(c) They sought to maximize the difference in money (or points) between their team and other teams

(d) They sought to minimize the difference in money (or points) between their team and other teams

5.  What does social identity theory NOT do a good job of explaining?

(a) Why people tend to ignore differences between people in out-groups

(b) Why people tend to think their group is the best

(c) Why people often overlook the flaws and shortcomings of their own group's behavior

(d) Why violence occurs between some groups but not others

​1 - D, 2 - A, 3 - A, 4 - C, 5 - D