Ep69 "Why We Don't Just Say What We Mean" with Steven Pinker

Quick Overview

Steven Pinker argues that the common knowledge assumption—where everyone knows that everyone knows a piece of information, like the Roman Emperor not wearing clothes—is a crucial, yet often overlooked, element of human behavior, especially in social dynamics, political regimes, and even in mathematics like game theory, because this shared awareness dictates how people act and coordinate, often leading to self-censorship or manufactured public agreement even when private knowledge contradicts the consensus.

Key Points: The concept of common knowledge, where everyone knows that everyone knows something, is a fundamental driver of human behavior across social, political, and mathematical contexts. Pinker cites the example of the Roman Emperor not wearing clothes, where the tacit agreement to pretend he is clothed maintains a societal equilibrium that direct contradiction would shatter. In political regimes, like dictatorships, this common knowledge equilibrium often involves people publicly conforming to the dictator's narrative while privately knowing it is false, fearing being the first to break ranks. The ability to engage in complex coordination, such as in marriage contracts or economic exchanges, relies on shared knowledge assumptions about mutual intent and beliefs. Cognitive psychology suggests that humans are naturally adept at tracking these nested beliefs (I know that you know that I know...), which is essential for social interaction. The failure to maintain common knowledge—or the fear of being the first to expose a shared secret—is what often prevents collective action or truth-telling in oppressive systems. Pinker suggests that education, particularly in areas like game theory and logic, can help people recognize and sometimes break these common knowledge equilibria.

Context: This is Part 1 of an interview between Jonathan Berke of the Lauder Institute and Steven Pinker, Johnstone Family Professor of Psychology at Harvard University, discussing Pinker's book on 'The Science Behind Why We Don't Just Say What We Mean.' The conversation centers on the concept of common knowledge—a formal, logical concept extended from mathematics and game theory—and its profound implications for understanding why individuals often fail to express their true private beliefs in public settings, particularly under oppressive social or political structures.