Groups systematically undervalue distinctive information that only one member holds

Evidence

Research has shown, for example, that individuals are more likely to discuss shared knowledge (aspects of what they know is part of their common knowledge) compared to unshared information (their distinctive or unique knowledge). This tendency contributes to what has been called the “common knowledge effect” (see Strasser, 1999, for a review). Because of this common knowledge effect, when uncommon information does happen to be introduced into a discussion the discussion of that information tends to be more cursory or muted. In short, distinctive and potentially valuable information tends to be undervalued and utilized. — Roderick M. Kramer, Geoffrey J. Leonardelli, Robert W. Livingston, Social Cognition, Social Identity, and…, 1981

Categorization

• XREF: Connects to Janis-style groupthink literature and to the general problem of information sharing in teams raised in organizational psychology and the law merchant material about information costs.
• SEED: Article angle: why the ‘mention it to the group’ meeting format actively suppresses the single most valuable piece of information anyone has — and what meeting designs counteract the common knowledge effect.
• DEFINE: Defines ‘common knowledge effect’ as a named, citable phenomenon.