Key Concepts in Social Psychology

Social influence is the process by which individuals adjust their thoughts, feelings, or behaviours in response to others. Two classic lines of research dominate this area.

Solomon Asch's conformity experiments (1951–1956) showed that people will publicly agree with an obviously wrong answer when surrounded by confederates who give that wrong answer unanimously. Around 75% of participants conformed at least once. The critical variable was unanimity: even a single dissenter dramatically reduced conformity. Asch's work distinguishes normative influence (going along to fit in) from informational influence (going along because you genuinely believe others know better).

Stanley Milgram's obedience studies (1961–1963) are among the most cited — and most debated — experiments in the history of psychology. Participants believed they were delivering escalating electric shocks to a learner; around 65% continued to the maximum voltage when instructed by an authority figure. The experiments revealed the power of situational factors — the presence of an authority, the physical distance from the victim, gradual commitment — over individual moral character. Milgram's work is frequently revisited in the context of real-world atrocities and institutional wrongdoing.

Key distinctions to know: compliance (public agreement without private belief), identification (adopting attitudes to be like an admired person), and internalisation (genuine private acceptance of a view).

Attribution theory concerns the causal explanations people construct for events and behaviours. Fritz Heider laid the foundations in 1958, distinguishing internal attributions (behaviour caused by the person — their ability, effort, or character) from external attributions (behaviour caused by the situation — luck, task difficulty, or social pressure).

Edward Jones and Keith Davis developed correspondent inference theory, describing how we infer stable personal dispositions from observed actions. Harold Kelley's covariation model (1967) formalised this further: we attribute behaviour to a cause that co-varies with it across consensus (do others behave the same way?), distinctiveness (does this person behave this way in other situations?), and consistency (does this person behave this way across time?).

The fundamental attribution error (FAE) — also called the correspondence bias — is the systematic tendency to overestimate dispositional causes and underestimate situational ones when explaining other people's behaviour. Ross (1977) named and popularised this bias. The error is weaker in collectivist cultures and when we are explaining our own behaviour (the actor-observer asymmetry).

The self-serving bias is the related tendency to attribute our successes to internal causes and our failures to external ones, protecting self-esteem. The just-world hypothesis — the belief that people get what they deserve — can be seen as a motivated attribution strategy that preserves belief in a fair world.

When individuals come together in groups, their behaviour changes in predictable and often counterintuitive ways.

Groupthink, described by Irving Janis (1972) from case studies of major US foreign policy failures (the Bay of Pigs, Pearl Harbor), occurs when a cohesive group prioritises harmony and unanimity over realistic appraisal of alternatives. Warning signs include illusions of invulnerability, collective rationalisation, stereotyping of outgroups, and self-censorship. Janis proposed structural remedies: assigning a devil's advocate, inviting outside experts, and breaking into sub-groups before reconvening.

Social loafing (Latané, Williams & Harkins, 1979) is the reduction in individual effort that occurs when people work collectively rather than alone. It is stronger when individual contributions are not identifiable, the task feels unimportant, and group cohesion is low. The Ringelmann effect — diminishing returns as group size increases in tug-of-war tasks — was the earliest empirical observation of this phenomenon.

Deindividuation refers to the loss of self-awareness and personal responsibility that can occur in groups, particularly in anonymising or arousing conditions. Zimbardo's work (and later Diener's) suggests that deindividuation lowers restraints on impulsive behaviour. The Stanford Prison Experiment (1971), while deeply methodologically flawed and never published in a peer-reviewed journal, remains culturally influential as an illustration of situational power in group roles.

Social facilitation (Zajonc, 1965) offers a counterpoint: the mere presence of others increases arousal, which improves performance on well-learned tasks but impairs it on novel or complex ones.