In psychology, prejudice is a negative attitude toward a group of people based solely on their membership in that group. It goes beyond simple dislike. Prejudice involves a combination of feelings, beliefs, and behavioral tendencies that together shape how someone perceives and responds to people they see as different from themselves. Understanding prejudice as a psychological concept means breaking it apart into its components and examining where it comes from, how it operates (sometimes without a person’s awareness), and what it does to the people on the receiving end.
The Three Components of Prejudice
Psychologists describe prejudice using what’s called the ABC model: affect, behavior, and cognition. These three elements work together but represent distinct pieces of the overall attitude.
The affective component is the emotional piece. It includes the negative feelings someone experiences toward members of another group: discomfort, anxiety, disgust, hostility, or fear. These emotions can arise automatically, sometimes before a person even has a conscious thought about why they feel that way.
The cognitive component involves beliefs about the personal attributes of a group. These are stereotypes: generalized assumptions that everyone in a group shares certain traits. Believing that members of a particular ethnic group are lazy, or that older workers can’t learn new technology, are cognitive expressions of prejudice. They provide the mental framework that justifies the negative feelings.
The behavioral component is what a person actually does as a result of those feelings and beliefs. This is discrimination: treating someone unfairly because of their group membership. It can range from subtle avoidance to overt hostility. While prejudice is the attitude, discrimination is prejudice in action.
Prejudice, Stereotypes, and Discrimination
These three terms are often used interchangeably in everyday conversation, but they refer to different things. A stereotype is a belief (cognitive). Prejudice is an attitude that includes emotions and behavioral tendencies. Discrimination is the behavior itself, usually the outward manifestation of prejudice involving negative or injurious treatment of people in rejected groups. You can hold a stereotype without acting on it. You can feel prejudice without discriminating. But in practice, the three tend to reinforce one another. The American Psychological Association defines discrimination as typically the behavioral manifestation of prejudice, making it the most visible and measurable consequence.
Explicit vs. Implicit Prejudice
One of the most important distinctions in prejudice research is between what people consciously endorse and what operates below their awareness. Explicit prejudice is the kind a person can report on directly. It involves conscious stereotyping and deliberate discriminatory behavior. If someone openly says they believe a certain group is inferior, that’s explicit prejudice. Researchers measure it through surveys and self-report questionnaires.
Implicit prejudice is trickier. It reflects unconscious associations between groups and positive or negative attributes. A person who genuinely believes in equality can still carry implicit negative associations toward certain groups, shaped by a lifetime of cultural exposure. The most widely used tool for measuring implicit prejudice is the Implicit Association Test, or IAT, which measures how quickly someone pairs positive and negative words with images of different groups. If you’re faster at pairing negative words with a particular group, it suggests an unconscious association. Research consistently finds that the IAT is the implicit measure most strongly associated with predicting actual choice behavior, though the relationship between implicit bias scores and real-world discrimination is modest.
Brain imaging research supports this conscious/unconscious distinction. When people make quick, superficial judgments about faces of other racial groups, the amygdala, a brain region involved in threat detection and emotional processing, shows increased activity. People with stronger implicit bias scores on the IAT show greater differences in amygdala activation when viewing faces of different racial groups. But when people are given meaningful information about individuals and asked to form thoughtful impressions, the prefrontal cortex, the part of the brain responsible for deliberate reasoning, suppresses that automatic amygdala response. In other words, the brain’s snap judgment system and its deliberate thinking system are often pulling in different directions.
Modern and Subtle Forms
Old-fashioned prejudice, the kind that openly endorses segregation or declares one group superior, has become less socially acceptable in many societies. But psychologists have identified subtler forms that persist.
Aversive prejudice describes people who explicitly believe in equality and rally against discrimination, yet unconsciously harbor negative associations toward out-group members. These individuals would never say anything overtly biased, but their unconscious attitudes leak out in ambiguous situations where they can rationalize their behavior on non-racial grounds. For example, an aversive racist might not discriminate when the right choice is obvious, but in a gray area, their decisions tend to favor their own group.
Modern prejudice takes a different form. People who hold modern prejudice believe that discrimination no longer exists and define racism narrowly as overt hostility. They tend to believe that any struggles a disadvantaged group faces are the group’s own fault, that demands for equality have gone too far, and that special programs to address historical disadvantage are unfair. Because they don’t see themselves as holding overtly hostile views, they don’t consider themselves prejudiced at all.
Where Prejudice Comes From
Several psychological theories explain why prejudice develops, and they aren’t mutually exclusive.
Realistic conflict theory, one of the most well-supported explanations, argues that prejudice arises when groups compete for limited resources like jobs, land, power, or social status. The classic demonstration came from Muzafer Sherif’s 1954 Robbers Cave experiment. Researchers divided 22 boys at a summer camp into two groups who didn’t know each other existed. Once the groups were formed, the researchers introduced competitions with trophies at stake. Prejudice emerged rapidly. At first it was verbal: taunting and name-calling. As competition continued, it escalated to burning the other group’s flag, ransacking cabins, and stealing property. When asked to describe the two groups, the boys rated their own group in glowing terms and the other group in harshly negative ones. The prejudice wasn’t there before the competition. Resource rivalry created it from scratch.
Social identity theory offers a complementary explanation. People naturally categorize themselves into groups and derive part of their self-esteem from those group memberships. To feel good about their own group, they tend to view other groups less favorably. This in-group favoritism can happen even when the groups are formed on trivial criteria and no competition exists.
Learning also plays a central role. Children absorb prejudicial attitudes from parents, peers, media, and cultural norms, often before they have any direct experience with the groups in question. The absence of positive contact with members of other groups leaves these learned attitudes unchallenged.
How Prejudice Affects Its Targets
Prejudice doesn’t just shape how people view others. It actively harms the people it targets, often in ways that go beyond direct discrimination.
Stereotype threat is one of the most studied mechanisms. It occurs when a person is aware that a negative stereotype exists about their group and fears confirming it. That awareness alone is enough to impair performance. The effect works through three interrelated pathways: a physiological stress response that directly disrupts the brain’s ability to process complex information, a tendency to anxiously monitor one’s own performance, and active mental effort spent trying to suppress the negative thoughts and emotions the stereotype triggers. Together, these processes consume the mental resources a person needs to perform well.
The impact is measurable. In experiments, women under stereotype threat recalled fewer words on working memory tasks than men in the same condition or women who weren’t reminded of gender stereotypes. When researchers accounted for the drop in working memory, the effect of stereotype threat on math performance became insignificant, confirming that the threat works by draining cognitive capacity. Black college students under stereotype threat also showed impaired performance on tasks measuring the ability to filter out irrelevant information, a core executive function.
The physiological toll is real as well. Black students performing a test described as measuring intellectual ability showed increased blood pressure compared to white students taking the same test. The stress response involves the same hormonal systems activated by acute social threats, including elevated cortisol levels that directly reduce the efficiency of higher-order thinking. Prejudice, in this way, creates the very performance gaps it claims to observe.
Reducing Prejudice
The most influential framework for reducing prejudice is the contact hypothesis, originally proposed by Gordon Allport in 1954. Allport argued that bringing members of different groups together could reduce prejudice, but only under the right conditions: the groups needed equal status in the situation, they needed to work toward common goals, there had to be no competition between them, and the contact needed support from authorities or institutional norms. Decades of research have confirmed that intergroup contact reliably reduces prejudice. Later work has found that Allport’s four conditions help maximize the effect but aren’t strictly necessary. Even casual, positive interactions across group lines tend to reduce prejudice to some degree.
At the individual level, the brain research on prejudice offers a practical insight. Because the prefrontal cortex can override automatic amygdala responses, deliberately thinking about people as individuals rather than as members of a group shifts neural activity away from threat-based processing and toward more thoughtful evaluation. This doesn’t erase implicit bias instantly, but it represents the cognitive mechanism through which people can regulate their automatic prejudicial responses in real time.