All 6 Terms & Definitions
- Bystander effect
- The phenomenon whereby individuals are less likely to help in an emergency when other people are present. Latané and Darley identified two mechanisms: pluralistic ignorance (each person looks to others for cues about how to interpret the situation and, seeing others doing nothing, concludes there is no emergency) and diffusion of responsibility (each person assumes someone else will take action).
- Diffusion of responsibility
- The tendency for individuals in groups to feel less personal responsibility for taking action because they assume others will act. The larger the group, the more responsibility is diffused. Diffusion of responsibility is a key mechanism underlying the bystander effect and social loafing.
- Group polarisation
- The tendency for group discussion to push members toward more extreme versions of their initial positions. If group members generally lean toward a risky option before discussion, discussion makes them more risk-accepting; if they lean cautious, discussion makes them more conservative. Group polarisation occurs through social comparison (wanting to be more extreme than average) and persuasive arguments (discussion exposes more arguments favouring the dominant view).
- In-group/out-group bias
- The tendency to favour members of one's own group over members of other groups, even when group membership is arbitrary and meaningless. Tajfel and Turner's minimal group paradigm showed that simply categorising people into groups leads to preferential treatment of the in-group. In-group bias underlies discrimination, stereotyping, and intergroup conflict.
- Social identity theory
- Henri Tajfel and John Turner's theory proposing that group membership is a central source of self-esteem. People are motivated to view their own groups positively — and by extension themselves — which drives in-group favouritism and out-group derogation. Social identity theory provides a motivational explanation for intergroup conflict and discrimination.
- Pluralistic ignorance
- A situation in which each member of a group privately holds a different belief from the apparent group norm, but assumes (wrongly) that their private view is the deviant one. Classic example: each student finds a lecture confusing but stays silent, assuming everyone else understands. Pluralistic ignorance sustains social norms that no individual member actually endorses.