stereotype, in psychology, a fixed, oversimplified, and often biased belief about a group of people. Stereotypes are typically rationally unsupported generalizations, and, once a person becomes accustomed to stereotypical thinking, he or she may not be able to see individuals for who they are. Stereotypes can legitimize hostility against a whole social group. In addition, because stereotypes are ingrained in the culture—people begin learning stereotypes during childhood—they tend to signal which social groups are presumably appropriate targets for relieving individual frustration.

(Read Steven Pinker’s Britannica entry on rationality.)

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Amy Tikkanen.

prejudice, adverse or hostile attitude toward a group or its individual members, generally without just grounds or before sufficient evidence. It is characterized by irrational, stereotyped beliefs. In the social sciences, the term is often used with reference to ethnic groups (see also racism), but prejudice can exist toward any manner of person or group on the basis of factors that have nothing at all to do with ethnicity, such as weight, disability, sexual orientation, or religious affiliation.

This article was most recently revised and updated by Jeannette L. Nolen.