Ben stereotypes gay men as being unathletic. When he meets Al, an athletic gay man, he assumes that Al is not a typical representative of gay people.

Liz has a stereotype of elderly people as mentally unstable. When she sees an elderly woman sitting on a park bench alone, talking out loud, she thinks that the woman is talking to herself because she is unstable. Liz fails to notice that the woman is actually talking on a cell phone.

Paul has a stereotype of Latin Americans as academically unmotivated. As evidence for his belief, he cites instances when some of his Latin American classmates failed to read required class material. He fails to recall all the times his Latin American classmates did complete their assignments.

The word stereotype has developed strong negative connotations for very good reasons. Negative stereotypes of different groups of people can have a terrible influence on those people’s lives. However, most people do rely on stereotypes nearly every day to help them function in society. For example, say a woman has to work late and finds herself walking home alone on a dark city street. Walking toward her is a group of five young men talking loudly and roughhousing. The woman crosses the street and enters a convenience store until the young men pass, then continues on her way. Most people would say she acted prudently, even though she relied on a stereotype to guide her behavior.

Some evolutionary psychologists believe that xenophobia, the fear of strangers or people different from oneself, has genetic roots. They argue that humans are to some extent programmed by their genes to respond positively to genetically similar people and negatively to genetically different people.

Rachel’s parents came from a working-class background but are now wealthy business owners. Rachel might develop a dislike of the working class because she does not want to be identified with working-class people. She believes such an association would damage her claim to upper-class social status.

Glen blames his unemployment on foreign nationals whom he believes are incompetent but willing to work for low wages.

A poor white farmer in the nineteenth-century South could feel better about his own meager existence by insisting on his superiority to African-American slaves.

Most religious and ethnic groups maintain some prejudices against other groups, which help to make their own group seem more special.

Pseudoscientific arguments about the mental inferiority of African Americans allowed whites to feel justified in owning slaves.

Hostility between an ingroup and an outgroup increases when groups compete. Researchers have found that hostility between groups decreases when those groups have to cooperate in order to reach a shared goal. In such a situation, people in the two groups tend to feel that they belong to one larger group rather than two separate groups.

Kurt Lewin is widely considered the father of social psychology. He developed many concepts that both psychologists and the general public now take for granted, including his “field theory” that a person’s behavior is determined both by that person’s character and by his current environment. Lewin also did important work in the area of majority-minority relations. In the mid-1940s, the American Jewish Council (AJC) began talking with Lewin about ways to reduce anti-Semitism. Shortly before his death in 1947, Lewin became chief consultant for the AJC’s Commission on Community Interrelations, a groundbreaking organization designed to combat prejudice through community intervention.