You've most likely heard the term stereotypes before, and also heard that its wrong to stereotype others.  But what exactly is a stereotype, where do stereotypes come from, and what effects to they have on behavior?
Try it Out

Take a look at the pictures of the three dogs below.

  • Write down three adjectives to describe each dog

  • Which dog would you most like to have as a pet?  Explain why
How are stereotypes created?
Did you describe the pit bull (the dog pictured on the left) as aggressive and fierce?  Or did you describe the golden retriever (the dog pictured in the middle) as loyal and friendly?  If so, you've made assumptions about each dog based on the stereotype of each dog's breed.  Since you have not actually met any of the dogs pictured above, your assumptions could turn out to completely false.  The dog on the left, despite being a pit bull, might actually be friendly and gentle, while the dog in the middle, despite being a golden retriever, might actually be hostile and unfriendly.  But don't feel bad about it - we all stereotype, whether we like it or not.

If we instantly form stereotypes about different types of dogs, who don't matter all that much to us, how much more so do we stereotype different types of people?  Of course, if I had shown an image of a Japanese person, a Mexican, and an African-American, and asked you to describe each of their personalities, alarm bells would start ringing - its wrong to judge a person by their race, you might reply.  But just because we know its wrong, it doesn't mean that we don't make assumptions about a person based on their appearance, whether we intend to or not.

stereotype is a widely held (but oversimplified) belief about the characteristics of a group.  They aren't necessarily all negative - stereotypes can be neutral or positive as well, such as the belief that Germans are punctual and efficient, or that Italians are passionate about food and football.  There are two cognitive processes that underlie stereotypes:

  • Categorization involves mentally placing someone into a particular social group, which could be based on their gender, age, race, nationality, occupation, religion, style of dress, or some combination of the above.  We categorize people instantly and automatically - it is impossible to see a person without noticing their gender, for example.  

  • Generalization involves forming a belief about a particular social group (ex. "Italians love pasta") and then applying that belief to all members of the group (ex. "Fabio is Italian, so he must love pasta").  Generalization occurs because of the out group homogeneity effect, which is the tendency to underestimate individual differences between people in an out group.  You surely know that people from your own country vary in their appreciation of food - some people are true gourmands who spend hours preparing a meal, while others will eat whatever happens to be in the fridge.  Yet we tend to underestimate these individual differences when thinking about people in an outgroup, incorrectly assuming that they all must share some common characteristics with one another - like the stereotype that French people all love cheese and wine.

​Think Critically

A common stereotype is that "Asians are good at Maths".  Reflect critically on this stereotype:

  • Where do you think this stereotype comes from?  Why do many people believe that Asians are better than other groups at Maths?

  • Do you think there is any truth to the stereotype?  You might want to refer to the graph below, which shows the top 10 countries on the PISA tests, which are standardized tests in Math, Reading and Science given to students across the world

  • Suppose a new student joins your school tomorrow, who happens to be Asian.  Is it reasonable to conclude that he or she will be good at Maths?  Explain why (or why not)

Are stereotypes true?
Although all stereotypes involve categorization and generalization, there is some disagreement over the extent to which stereotypes are true.

According to Campbell, stereotypes often have a grain of truth to them.  In other words, maybe Asians really are better at Maths, at least on average.  The results from the PISA test seem to support this - the top 7 countries for Maths are all located in Asia.  According to Campbell, stereotypes are formed in two ways:

  • Personal experiences with people from another group - for instance, if you notice that your Asian classmates always tend to be amongst the best in Maths classes, that can create the stereotype

  • Gatekeepers from our group, such as our parents or members of the media, that influence how our group perceives members of other groups.  For instance, in American TV and movies, Asians are often cast in roles - such as computer engineer or scientist - that reinforce the stereotype of Asians being good at Maths

Contrary to Campbell, who suggests that stereotypes often have a grain of truth, Hamilton argues that stereotypes are often completely false.  Have you ever heard the stereotype of the "dumb blonde"?  This is a good example of a stereotype that is almost certainly false - there is no correlation at all between IQ scores and hair color!  So if many stereotypes are completely false, where do they come from?  Hamilton suggests these two ways:

  • Illusory correlation refers to seeing a relationship (a correlation) between two variables (such as hair color and intelligence) when, in fact, none exists.  Illusory correlations can exist because of the confirmation bias, explained below.

  • Confirmation bias refers to a basic human tendency to seek out information that confirm a belief, and to ignore information that challenge a belief.  For instance, if you really think that blondes are dumb, you'll really notice examples of blondes doing dumb things, and pay less attention to examples of brunettes (or others) doing equally dumb things.  This reinforces the illusory correlation between hair color and intelligence.  When Sarah (who is blonde) does something dumb, you'll think "See, I knew blondes were dumb!" but when Jessica (who is brunette) does something dumb, you'll think "Wow Jessica is dumb" - not "brunettes are dumb!"

Who is correct, Campbell or Hamilton?  The answer likely varies from stereotype to stereotype.  There are some stereotypes that likely have a grain of truth to them, while others are completely false.

However, even if some stereotypes do have a grain of truth to them, it is important to remember that what may true on a group level doesn't apply to each individual within the group.  There are certainly many Asians who are not particularly good at Maths, and it would be wrong to make conclusions about any particular individual - such as a new Asian student at your school - on the basis of a stereotype alone.  That new Asian student might be passionate about music and poetry, and helpless in Maths.  Stereotypes are simplified beliefs, while the truth is that members of any group vary tremendously.
Effects of stereotypes
Stereotypes are linked to prejudice and discrimination - for instance, research has suggested that African-Americans often face more difficulty finding a job than people of other races (even when equally qualified) because of persistent negative stereotypes about African-Americans in the United States.  For an example of a research study on prejudice and discrimination, take a look at this article.

Stereotypes do not only influence how other people treat us - they also influence how we think about ourselves.  If you are exposed to negative stereotypes about your group, these stereotypes might make you more anxious, and that anxiety might end up hurting your performance - a phenomena known as stereotype threat.  For instance, a common stereotype in the United States is that girls are somehow less able than boys when it comes to Maths.  Being a girl, and being aware of this stereotype, you might get very nervous every time you are given a Maths test, causing you to do worse on the test than you otherwise would have.  On the other hand, positive stereotypes can have the opposite effect, increasing your confidence and leading to a stereotype boost, in which increased confidence leads to even better performance.

Shih carried out a very clever study on stereotype threat and stereotype boost on Asian-American women, who were chosen because they are exposed to conflicting stereotypes - their gender is associated with poor Math ability, while their race is associated with skill in Maths.  Which stereotype will have the greater effect?  That depends on whatever stereotype you happen to be thinking about at the moment, as the following study illustrates.

​Research - Shih et al

Aim: Investigate how negative stereotypes about your group can hurt performance (stereotype threat) while positive stereotypes can improve performance (stereotype boost)


  • Participants were 46 Asian-American women studying in an elite American university, and were randomly assigned to three groups

  • In group 1, participants were asked to complete a questionnaire that reminded them of their identity as females.  For instance, they were asked whether their dorm was female-only or mixed gender, and to list some reasons why they preferred a female-only dorm or a mixed gender dorm

  • In group 2, participants were asked to complete a questionnaire that reminded them of their identity as Asian.  For instance, they were asked whether they or their parents spoke other languages besides English, and how often they spoke these languages at home and on campus

  • Group 3 served as the control group, with no questionnaire given

  • Afterwards, all participants were given a test made up of difficult Math problems


  • Participants reminded of their gender performed significantly worse on the Math test compared to the control group

  • Participants reminded of their race did significantly better compared to the control group


  • When reminded of their gender, negative stereotypes about women and Maths caused increased anxiety and worse performance, illustrating stereotype threat

  • When reminded of their race, positive stereotypes about Asians and Maths caused increased confidence and better performance, illustrating stereotype boost


  • The use of Asian-American participants was very effective in this study, as it allowed both stereotype threat and stereotype boost to be seen in the same group of participants

  • This was a laboratory experiment, demonstrating a clear causal relationship between the independent variable (which stereotype was brought to mind) and the dependent variable (performance on the Maths test)

  • The sample size was relatively small, and the difference in Maths performance between each group was also slight, so it is important to replicate this study with bigger sample sizes to confirm that the results are reliable

  • All participants in this study were of the same gender and race, and all were students at the same elite American university, so these results may not generalize to other racial, social and age groups


  • I can state the definition of a stereotype
  • I can explain how categorization, generalization, and the out group homogeneity effect contribute towards the creation of stereotypes

  • I can contrast two theories on whether stereotypes are true - Campbell's grain of truth hypothesis (based on personal experiences and gatekeepers), and Hamilton's explanation of how stereotypes can be completely false (based on illusory correlations and the confirmation bias)

  • I can explain some of the effects of stereotypes - including prejudice, stereotype threat, and stereotype boost

  • I can describe the Aim, Procedure, Findings and Conclusion of the research study by Shih on the effects of stereotypes, and can evaluate the study
Quiz Yourself!

1.  John goes on holiday to Australia.  Unfortunately, he forgets his wallet in the taxi from the airport.  Later that evening, the taxi driver returns the lost wallet to John's hotel.  John thinks, "Wow, Australians are so honest!".  Which cognitive process contributed to John's belief?

(a) Generalization

(b) Out group homogeneity effect

(c) Both A and B

(d) Neither A nor B

2.  Which statement about stereotypes is false?

(a) Stereotypes are widely held beliefs

(b) Stereotypes are always false

(c) Stereotypes are over-simplified

(d) Stereotypes are not always negative

3.  The Disney movie "Alladin" has come under criticism for reinforcing negative stereotypes of Arabs.  This illustrates which of the following:

(a) Grain of truth hypothesis

(b) Gatekeepers

(c) Illusory correlation

(d) Grain of truth hypothesis

4.  In one scene from the movie "8 Mile", a white rapper (based on Eminem) gets nervous and "chokes" in front of a crowd that doubts the ability of a white person to rap.  This scene illustrates which of the following:

(a) Grain of truth hypothesis

(b) Confirmation bias

(c) Illusory correlation

(d) Stereotype threat

5.  What statement is FALSE about the results of Shih's study?

(a) Being reminded of a positive stereotype can help you perform better

(b) Being reminded of a negative stereotype can hurt your performance

(c) A stereotype impacts performance only when it is brought to mind at that moment

(d) People do best when they are free from the effects of stereotypes


​1 - C, 2 - B, 3 - B, 4 - D, 5 - D