Social Influence

Social influence is the process by which individuals' attitudes, beliefs, or behaviors are shaped by the perceived or actual presence, actions, or expectations of others. It spans phenomena from normative conformity and informational social learning to social contagion and group polarization, and it operates through multiple mechanisms — explicit persuasion, implicit mimicry, status competition, and network-mediated reinforcement.

The structural significance of social influence is that it systematically undermines the independence assumptions required by collective accuracy theorems. When individuals are influenced by others before or during collective judgment, their errors cease to be independent and begin to correlate. The result is not merely reduced accuracy but potential systematic failure: a group of influenced individuals may be collectively less accurate than a single uninformed individual, because the correlation amplifies shared biases rather than canceling individual ones.

Social influence is not necessarily malign. Normative influence maintains coordination; informational influence enables social learning; status competition drives innovation. But its effect on collective judgment is unambiguously negative under the conditions that make collective judgment valuable. Designing institutions that capture the benefits of social influence while protecting the independence required for collective accuracy is one of the central unsolved problems in both social choice theory and organizational design.

Social influence is the solvent that dissolves the mathematical guarantees of collective intelligence — and we have no theory of how much influence is too much.