The Social Functions Of Common Knowledge

"In When Everyone Knows That Everyone Knows, Steven Pinker (a professor of psychology at Harvard University and, author, among many books, of Rationality, The Stuff of Thought, How the Mind Works, and The Better Angels of Our Nature) draws on research in the cognitive and behavioral sciences, game theory and linguistics to provide a wide-ranging, far-reaching, and fascinating examination of the multiple layers of "common knowledge.""

"Conspicuous emotional expressions, Pinker indicates, are "common-knowledge generators." Laughter can challenge conventions of dominance, status, and prestige. Apparent to everyone in sight, crying can convey feelings of helplessness, abandonment, and also, counterintuitively, joy and compassion. Blushing sends a message that one has, albeit involuntarily, been thrust in the spotlight. Most people are mortified when their blush is followed by eye contact and becomes common knowledge."

"Most people prefer thinly veiled propositions, even when they don't "pass the giggle test," to blatant sexual come-ons or bribes, even when the latter pose little or no cost to them, because direct speech generates common knowledge, while denying the implications of an inuendo "doesn't have to be plausible, only possible." People are more likely to flourish, Pinker reminds us, when they coordinate their actions with others."

Common knowledge operates at multiple layers of social life, shaping coordination, stability, cohesion, and change across families, workplaces, neighborhoods, religious and political communities, and nation-states. Conspicuous emotional expressions act as common-knowledge generators: laughter can upend dominance hierarchies, crying signals helplessness or compassion, and blushing marks involuntary exposure that becomes socially salient. People favor indirect, thinly veiled signals over explicit offers because direct speech creates common knowledge, making implications public. Common knowledge is amplified and complicated by social media, which both generates and disseminates shared beliefs and expectations that influence individual behavior and collective outcomes.

Read at Psychology Today