Stereotypes are widely held evaluative generalizations about a group of people (Aronson et al. 2007). They are characteristics assigned to all members of a group, in spite of the individual differences between the members. Stereotypes can be based on gender, age, race, beliefs, culture, ethnicity etc.
Stereotypes can be both positive or negative and greatly contribute to the prejudice and discrimination in our society. There are many theories that explain why and how they are formed, for example, the illusory correlation, confirmation bias and the social-cognitive theory. They can be formed due to illusory correlation whereby a trait is assigned to a group without any relationship between the two variables. They can also be formed due to confirmation bias, where we only focus on our predisposed impressions and disprove or ignore opposing other factors. Stereotyping is a way in which we categorize a large amount of social information into different groups depending on the typical characteristic displayed by different groups (social cognitive theory). Campbell (1967) argues that it is formed due to the grain of truth hypothesis which states that if a trait were to be attributed, it must have a reason.
As the oversimplified generalizations are made and subconsciously ingrained, our behavior towards certain individuals, depending on their stereotype, could change. For example, the stereotype for an elderly person might be a person with grey hair, wrinkles and mobility difficulties, so the way we behave around an individual that has that stereotype, we move slower to adjust to their pace and be more careful. The study of Spencer et al. (1977) which demonstrated the potential danger of stereotyping. This study involves the mathematical testing of male and female participants. The participants were told (put under stereotype threat), before they had done the test that females would under-perform and males are better at math. The researchers found that this resulted in the female participants scoring lower than the males. However, a literature test was performed where the participants were not put under any stereotype threat and found that male and female scored almost equally well. This study shows that when under stereotype threat, we tend to act according to the stereotype whether its conscious or subconsciously.