Social facilitation A process whereby the presence of others enhances performance on easy tasks but impairs perfor- mance on difficult tasks.
Social identity model of deindividuation effects (SIDE) A model of group behavior that explains deindividuation effects as the result of a shift from personal identity to social identity.
Social identity theory The theory that people favor ingroups over outgroups in order to enhance their self-esteem.
Social impact theory The theory that social influence depends on the strength, immediacy, and number of source persons relative to target persons.
Type A personality A pattern of behavior characterized by extremes of competitive striving for achievement, a sense of time urgency, hostility, and aggression.