GD POLITICS: Steven Pinker On The Coordination Game Of Politics
GD POLITICS Podcast, Host: Galen Druke, Guest: Steven Pinker
Date: October 16, 2025

Episode Overview

In this episode, Galen Druke talks with acclaimed Harvard psychologist and author Steven Pinker about his latest book, When Everyone Knows that Everyone Knows: Common Knowledge and the Mysteries of Money, Power, and Everyday Life. The focus is on the game theory concept of common knowledge—the idea not just of knowing something, but knowing everyone else knows it, and so on—and its profound implications for politics, negotiation, culture, and daily life. Pinker explains how common knowledge enables coordination among individuals and groups, influences events from Super Bowl ads to high-stakes diplomatic summits, and how the internet and social media are radically reshaping our relationship to these dynamics.

What Is Common Knowledge? [00:00–04:00]

• Definition in Game Theory:
  • Pinker distinguishes everyday “common knowledge” (what everyone knows) from the technical definition: a fact everyone knows, everyone knows everyone else knows it, and so on infinitely.
    • “Common knowledge refers not to something that everyone knows, but to something that everyone knows that everyone knows, and everyone knows that, and so on ad infinitum.” – Steven Pinker [02:44]
• Why It Matters:
  • Common knowledge is essential for coordination—allowing people to make matching choices that only work if both parties are aware of a mutual expectation.
    • “Common knowledge is necessary for coordination, for two people to be on the same page and make complimentary choices that only work if both of them make it.” – Pinker [03:21]

Examples and Mechanisms [03:56–09:00]

• Coordination in Everyday Life:
  • Simple decisions, like meeting a friend for coffee, require more than just individual knowledge or preference; they require shared knowledge.
• Role of Language & Broadcasts:
  • Language and mass communication (like TV in its heyday) create common knowledge instantly.
    • “One of the ways we do that is with language. That’s, I think, why we evolved language: it’s an excellent common knowledge generator.” – Pinker [05:30]
• Suppression of Common Knowledge:
  • People deliberately avoid making some knowledge “common” to preserve relationships or avoid social fallout (e.g., polite euphemisms, “the elephant in the room”).
    • “Conversely, we often try to keep things out of common knowledge... that’s where we get into the whole world of genteel hypocrisy, euphemism, innuendo, politeness, beating around the bush…” – Pinker [05:55]

Technology and the Expansion/Fragmentation of Common Knowledge [06:11–08:36]

• Mass Communication vs. Social Media:
  • In the past, mass events like TV news broadcasts or the Super Bowl served as engines of national common knowledge.
  • Social media fragments this, creating echo chambers where people mistakenly believe their “feed” is communal knowledge.
    • “Broadcast media…generated a pool of common knowledge that was almost nationwide... That’s harder to do…when it comes to social media, where the feeds are delivered in a unique feed determined by an algorithm.” – Pinker [07:21]
• Echo Chambers:
  • “There’s that illusion that social media generates that what you’re seeing is common knowledge, or at least common knowledge... specific to some network of information sharing.” – Pinker [08:16]

Super Bowl Ads: Creating Common Knowledge for Commerce [08:36–14:05]

• Super Bowl as a Coordination Mechanism:
  • Certain products (Macintosh, Discover Card, Monster.com, movies, beers, sneakers) depend on network effects: you need to know others also use them.
  • Super Bowl ads are valuable because both viewers and advertisers know “everyone else” is watching, creating confidence to buy, try, or join.
    • “It wasn’t the sheer size of the audience, but the knowledge that everyone is watching the Super Bowl that made advertising uniquely worthwhile.” – Pinker [10:37]
• Cryptocurrency Example:
  • Crypto Super Bowl ads didn’t explain the technology—they simply conveyed, “others are jumping in now,” fueling bubbles via common knowledge, not content.
    • “There’s a speculative bubble that’s inflating. If you buy now and sell soon, you could make a profit. And you knew when you were watching that ad other people were watching that ad, inflating the bubble.” – Pinker [13:11]

Diplomatic Negotiations and the Role of Common Knowledge [14:05–21:48]

• Coordination Dilemmas in Bargaining:
  • Negotiations (e.g., a ceasefire in Israel-Hamas conflict) are solved partly via “focal points” or “Schelling points”—solutions that both sides can identify as natural, obvious choices.
    • “When there isn’t literally common knowledge...a focal point, something that just jumps out…can solve the coordination problem.” – Pinker [15:24]
• Madman Strategy & Escalation:
  • Making unpredictable, seemingly irrational moves (e.g., locking the steering wheel in ‘chicken’) can force the other party’s hand by broadcasting your commitment.
    • “There are two disadvantages to a madman strategy: one is if the other guy tries it at the same time…then of course it leads to disaster.” – Pinker [20:22]

Transparency, Face, and Legislative Negotiation [21:48–25:51]

• Downsides of Too Much Common Knowledge:
  • New transparency (C-SPAN, 24/7 news, social media) makes it harder for legislators to compromise because being seen to concede is a loss of “face”.
    • “Common knowledge does in informal interactions is it ratifies social relationships...We keep things out of common knowledge by using euphemism or innuendo or genteel hypocrisy.” – Pinker [22:33]
    • “Making concessions…also concedes not only the point under dispute, but also your preeminence, your resolve, your status in the relationship.” – Pinker [24:06]
• Metaphor of “Face”:
  • “We have the expression saving face, losing face. Interestingly, the face is the part of you that sees while being seen. And so it’s a perfect metaphor for common knowledge.” – Pinker [24:33]

Voting, Bandwagon Effects, and Momentum [25:51–29:47]

• Voting as a Coordination Game:
  • Voters often want to pick winners, not just their own preferences; polling, primaries, and perceived momentum shape “who everyone else is supporting.”
    • “If everyone is trying to outguess the other voters…some minor trivial event, if it is public, can create a positive feedback loop, a runaway spiral and determine the outcome of the race.” – Pinker [27:28]
• Gaffes and Self-Fulfilling Prophecy:
  • Political gaffes become doom loops if they enter the common knowledge circuit.
    • Example: Howard Dean’s “scream” in 2004—trivial in itself, fatal because “everyone knew” it meant doom for his campaign.
    • “For some reason everyone knew Dean’s candidacy was doomed because he gave a victory scream. What that had to do with fitness to be president is unclear. But what it did have to do with it was a self fulfilling prediction that voters are going to bail.” – Pinker [29:09]

Cancel Culture, Social Norms, and Unraveling [29:47–34:25]

• Norms and Social Enforcement:
  • Social norms exist and persist because of common knowledge; once broken publicly without punishment, they can unravel rapidly.
    • “A norm isn’t enforced by the police. It exists because everyone assumes that it exists…they are fragile to unraveling if they are flouted…and not punished.” – Pinker [30:34]
• The Role of Social Media:
  • Social media makes it easy to enforce or destroy norms via mass shaming.
    • “The whole phenomenon of social media shaming mobs and cancel culture comes when people want to prop up a norm by ensuring that anyone who flouts it in public is punished in public.” – Pinker [31:14]
• Changing Norms—Trump/Musk Example:
  • The career of Donald Trump, and more recently Elon Musk, shows how once-forbidden behaviors become normalized if “common knowledge” shifts.
    • “What he showed was your career wouldn’t be over. The norms against…blatant lying, insulting…what used to be a norm...the prediction is that the norm no longer existing would then open the floodgates to others.” – Pinker [33:14]

Optimism, Trends, and The Role of Common Knowledge [34:25–39:20]

• Pinker’s Perspective:
  • He distinguishes between perception (“events” fill the news) and data (“trends” often show progress).
    • “As we get better at reporting events…the news cycle accelerates, so we’re bombarded with things that go wrong. The things that go right are either things that don’t happen…or things that build up a few percentage points a year, but no one notices it.” – Pinker [35:30]
• Progress and Regression:
  • While global metrics on poverty, health, and education have improved overall (“raw fact”), areas such as democracy and women’s rights show recent dips.
    • “In other things, there’s been a kind of a drooping…Democracy is one of them, where the world is a little less democratic than it was 20 years ago. Women’s rights…has gone down a bit.” – Pinker [37:45]
• Is Common Knowledge Good or Bad?
  • “It’s not a question that I could easily answer. It’s like, is the law of gravity a cause for optimism or pessimism? It’s the law of gravity. We have to deal with it.” – Pinker [39:20]

Social Media, Youth, and Mental Health [40:17–42:55]

• Phones, Screens, and Well-being:
  • Pinker admits increasing openness to research linking social media to psychological distress, especially in young girls.
    • “The evidence is getting better that social media use certainly is associated and may cause declines in mental health...If I was a 14 year old girl and my entire life was the social media universe...that could be devastating.” – Pinker [41:15]
  • Social media time is time not spent in healthier activities: in-person interaction, exercise, nature, etc.

Notable Quotes

• “Common knowledge is necessary for coordination, for two people to be on the same page and make complimentary choices that only work if both of them make it.” – Steven Pinker [03:21]
• “Broadcast media…generated a pool of common knowledge that was almost nationwide.” – Pinker [07:21]
• “A norm…exists because everyone assumes that it exists…they are fragile to unraveling if they are flouted in a public forum and not punished also in a public forum.” – Pinker [30:34]
• “The law of gravity…We have to deal with it. Likewise, the dynamics of common knowledge...What I try to do is lay out the kind of the laws, the basic processes, the toolkit for understanding these phenomena.” – Pinker [39:20]

Key Takeaways

• Common knowledge is not just about widespread belief, but about awareness of others’ beliefs, enabling both large-scale and small-scale cooperation and coordination.
• Mass communication once served as the main driver of common knowledge, but social media has fragmented and sometimes artificially created it.
• Political and commercial strategies often hinge on generating or suppressing common knowledge—whether through Super Bowl ads, orchestrated momentum, diplomatic posturing, or controlling information.
• Modern technology amplifies both the benefits and drawbacks of common knowledge: coordination, social enforcement, conformity, but also polarization, public shaming, and fragility of norms.
• Pinker remains empirically focused: progress happens through trends, but our perception is heavily shaped by visible events and the common knowledge created by today’s hyper-connected world.

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