Social categorization is efficient but leads to stereotyping and prejudice. Bottom-up processing is based on others’ observable characteristics; top-down processing is based on knowledge stored in memory. Physical features (e.g., skin tone and face shape) cue categorization: Prototypical faces are processed quickly; ambiguous faces are difficult to categorize, which can result in a bias toward categorizing people as members of minority groups. The minimal group paradigm demonstrates how easily people are placed into ingroups and outgroups. The outgroup homogeneity effect leads people to see outgroup members as similar and ingroup members as unique. The cross-racial identification bias refers to people’s difficulty in distinguishing among outgroup members. In the ultimate attribution error, the ingroup’s negative behaviors are attributed to situational factors but the outgroup’s negative behaviors are attributed to personal characteristics. Perceivers feel indifferent toward dehumanized people and treat them negatively, sometimes resulting in hate. People learn stereotypes from the media and by observing the world around them, as predicted by social role theory. Illusory correlations develop when two characteristics are inaccurately linked. Language-based biases include the man-first principle, the tendency for men to be mentioned before women, and accent bias. Researchers debate whether stereotypes are somewhat accurate.