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

Key Concepts

• Common Knowledge: Not merely shared information, but mutual awareness that everyone else also possesses the information, iterated infinitely (everyone knows that everyone knows that everyone knows…).
• Coordination Games: Situations where individuals benefit from making the same choice, like driving on the same side of the road or maintaining a relationship.
• Focal Points: Salient cues or events that help individuals coordinate in the absence of explicit rules.
• Implausible Deniability: The ability to credibly deny knowledge or intent, even when it’s likely others suspect the truth.
• Private Knowledge: Information known to individuals but not shared publicly, lacking the iterative awareness of common knowledge.
• Common Knowledge Generators: Actions or events (like public announcements or rituals) that establish common knowledge.
• Chunking: A cognitive process of grouping information into meaningful units to overcome limitations in working memory.

The Importance of Common Knowledge Beyond Game Theory

The podcast episode centers around Steven Pinker’s book, What Everyone Knows That Everyone Knows, and explores the significance of common knowledge in human behavior, moving beyond its traditional role as a mathematical tool in game theory. Jules Van Binsburgen and Jonathan Burke, the podcast hosts, initially acknowledge using the concept of common knowledge daily in their work but hadn’t considered its fundamental importance until reading Pinker’s book. They define common knowledge not simply as shared information, but as a recursively understood awareness – “everyone knows that everyone knows that everyone knows…” – a crucial distinction from basic shared information.

The Emperor’s New Clothes: A Classic Illustration

The hosts use the anecdote of “The Emperor’s New Clothes” as a prime example. Each individual observes the emperor’s lack of clothing, possessing a piece of information. However, this information doesn’t become common knowledge until the boy’s public proclamation, at which point the iterative awareness is established – everyone knows everyone knows the emperor is naked – and the social equilibrium shifts dramatically. This illustrates the power of common knowledge compared to simply having information available. The initial silence stems from a fear of being the only one perceiving the truth, highlighting the importance of mutual confirmation.

From Linguistics to Human Interaction: Pinker’s Perspective

Steven Pinker explains his journey to studying common knowledge began with observations in linguistics. He noticed people rarely communicate directly, opting for euphemisms, innuendo, and hints. He argues this isn’t simply about politeness or computational complexity, but about avoiding challenges to ongoing relationships. Direct statements create common knowledge, potentially disrupting the established dynamic, while indirect communication generates private knowledge – both parties understand the intent, but it doesn’t become universally known. He introduces the concept of “implausible deniability,” a term suggested by the hosts, as a key component of this dynamic.

Coordination Games and Relationships

Pinker frames human relationships as “coordination games,” similar to choosing which side of the road to drive on. Successful relationships require both parties to make the same choices, and these choices must be common knowledge. Rituals, like weddings, serve as “common knowledge generators,” publicly announcing a new equilibrium and establishing shared understanding. He credits Michael Schwab’s work on “rational ritual” for highlighting this function.

The Dark Side of Common Knowledge: Collective Action & Scapegoating

The discussion extends to the potentially negative consequences of common knowledge. Pinker references Thomas Schelling’s work on collective action, explaining how a shared outrage or “incident” can trigger a coordinated response, sometimes leading to harmful outcomes like riots or pogroms. He cites examples like the Arab Spring, the Romanian revolution, and the Black Lives Matter movement, demonstrating how a single event can generate common knowledge and mobilize collective action, for better or worse. He emphasizes that coordination can be both beneficial and destructive.

Totalitarian Regimes and the Paradox of Prohibition

The conversation explores the strategies of totalitarian regimes. While seemingly counterintuitive, Pinker and the hosts discuss whether explicitly prohibiting certain topics actually creates focal points, potentially leading to the regime’s downfall. The hosts speculate that regimes often avoid explicit lists of forbidden topics, relying instead on ambiguous enforcement and creating an atmosphere of uncertainty. This aligns with the idea that a clear prohibition can establish common knowledge of the suppressed idea, potentially sparking resistance. Pinker notes that the lack of explicit rules can be oppressive in itself, as individuals are unsure what actions will be punished.

Cognitive Limits and the Role of "Chunking"

The hosts question whether individuals can train themselves to process more layers of embedded knowledge ("I know that you know that I know…"). Pinker introduces the concept of “chunking” from cognitive psychology, suggesting that we overcome cognitive limitations not by increasing brainpower, but by grouping information into meaningful units. This allows us to handle more complex thoughts by labeling and recombining pre-existing knowledge structures. He argues that social skills develop through practice and experience, allowing us to navigate complex social situations more effectively.

Conclusion

The episode convincingly argues that common knowledge is far more than a mathematical construct; it’s a fundamental aspect of human behavior, shaping our interactions, relationships, and even political movements. Pinker’s work highlights the importance of understanding the recursive nature of awareness – not just what people know, but what they know that others know – and its profound impact on social dynamics. The discussion underscores the power of common knowledge to both facilitate cooperation and incite conflict, and raises important questions about the role of information control in shaping social outcomes. The podcast promises a second part to further explore these complex ideas.