What Everyone Knows You Know with Steven Pinker

Summary

StarTalk Radio: “What Everyone Knows You Know” with Steven Pinker

Host: Neil deGrasse Tyson
Guests: Steven Pinker, Chuck Nice, Gary
Date: January 23, 2026

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Episode Overview

In this Special Edition of StarTalk Radio, Neil deGrasse Tyson welcomes renowned cognitive psychologist Steven Pinker to discuss the concept of common knowledge—what it is, how it shapes human society, and its impact on everything from economics and politics to comedy, relationships, and cultural norms. Drawing from Pinker’s latest book, “When Everyone Knows that Everyone Knows: Common Knowledge and the Mysteries of Money, Power And Everyday Life,” the conversation dives into the power of shared understanding, coordination, social signaling, and the profound role these mechanisms play in maintaining (or dissolving) the fabric of civilization.

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Key Discussion Points & Insights

1. Defining Common Knowledge

• What is Common Knowledge?
  • Pinker distinguishes between private knowledge (“everyone knows something”) and common knowledge (“everyone knows that everyone knows, and so on, ad infinitum”) [06:00].
  • Quote (Pinker, 05:54):

    “Common knowledge, in the technical sense, refers to the situation where I know something. You know it. I know that you know it, you know that I know it… ad infinitum. So it's when everyone knows that everyone knows.”

2. Common Knowledge and Social Coordination

• Why It Matters:
  • Coordination: It enables humans to align actions, expectations, and social roles—“civilization depends on common knowledge” [07:40]. Institutions (government, money, corporations) exist because people share a mutual recognition of their roles and value [08:13].
  • Example: The value of money arises only because “everyone knows it is valuable, and everyone knows that everyone knows it is valuable” [07:38].
• Thomas Schelling’s Example: A couple lost in pre-cell phone Manhattan must rely on shared conventions to find each other, illustrating the need for common knowledge to coordinate (e.g., both guessing a “public” meeting place) [09:00].

3. Human Signaling, Euphemism, and Acceptable Duplicity

• Weasel Words and Plausible Deniability:
  • Social interactions often avoid full explicitness, maintaining plausible deniability—think of euphemisms (“Netflix and chill”), veiled bribes, and innuendo to protect relationships and “save face” [15:37, 16:22].
  • Quote (Pinker, 17:18):

    “It's a plausible deniability of common knowledge. Because when you think about it, it's really not that plausible.”

4. Nonverbal Communication as Common Knowledge Generator

• Laughter, Blushing, Crying, Eye Contact:
  • These conspicuous non-verbal displays make private experience public, generating shared understanding about someone’s feelings or intentions.
  • Eye Contact: Among primates (including humans), it can signal threat, seduction, or the creation of mutual awareness (the “infinite loop” of “I know you know I know,” etc.) [28:29, 30:24].
  • Quote (Pinker, 25:04):

    “I suggest that they [laughter, crying, blushing] are common knowledge generators. So when you're laughing, you know you're laughing… Other people know you're laughing… and so on. Blushing… You feel the blood, others see the color change… They know that you know you're feeling it.”

5. Common Knowledge and Cultural Variation

• Cultural Context: What’s commonly known—and how certain resources (money, favors, sex) or relationships are treated—varies widely across cultures [22:21, 23:23].
  • Pinker explains three relationship models: communal, hierarchy/dominance, transactional [22:21].
  • Culture shock happens when you don’t know a new culture’s common knowledge [23:36].

6. Comedy, Education, and Solidarity

• Jokes and Pedagogy:
  • Comedy (and education) depends on shared common knowledge; a punchline only lands if the audience “gets it” [40:11].
  • Humor signals solidarity and “bonds people” because recognizing a joke identifies mutual understanding [41:37].
  • Quote (Pinker, 41:37):

    “If you get the joke, then what has just been made public is something that you privately knew all along. …That’s why humor is such an important bonding agent.”

7. Contagious Phenomena: Bank Runs and Toilet Paper Panics

• Virulence of Common Knowledge:
  • Public rumors (even jokes) can trigger mass behavioral cascades—e.g., bank runs, toilet paper shortages [44:02, 47:16].
    • Johnny Carson’s Joke: A Tonight Show quip about a “toilet paper shortage” created an actual shortage via public panic [47:16].
    • “The only thing we have to fear is fear itself” (Roosevelt) as a practical application of common knowledge theory [44:02].

8. Politics, Social Norms, and Fractured Common Knowledge

• Norm Shattering:
  • Norms exist only so long as people believe they do. Trump (and others) flouting expectations undermined decades-old conventions by publicly violating norms and facing few consequences—copycats then follow [50:31].
  • The fracturing of common knowledge, through media bubbles, leads to increased polarization and the erosion of shared facts [51:05].
• Quote (Pinker, 53:28):

  “There was a norm in politics… that you pretend that you like them even if you don't. And those are some of the norms that are shattered. You don't lie blatantly. … You at least try to pretend that you're honest.”

9. Danger of Distorted (or Weaponized) Common Knowledge

• Polarization: “Negative polarization” means not only disagreement, but mutual vilification. Social networks, cable news, and social sorting have created separate pools of common knowledge, increasing divisiveness and fueling conflict [51:05].
• Advice for Repair: Norms of civil disagreement, epistemic humility, and charitable interpretations in arguments could help restore healthy dialogue [55:18].
  • Mathematical Note: Pinker references Robert Aumann’s theorem that rational agents should not “agree to disagree,” advocating for dialogue aimed at convergence, not combat [56:04].

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Notable Quotes & Memorable Moments

On Common Knowledge and Civilization:

• “Civilization does depend on common knowledge, on institutions like government, like money. The only reason… a piece of paper… is valuable is because other people treat it as valuable.” — Pinker [07:40]

On Euphemism:

• “You're completely manipulating the buyer.” — Chuck Nice jokes about Pinker's provocative book title [05:48]

On Blushing and Universality:

• “[Darwin] used similarity in facial expressions… as an argument against… scientific racism of his day… we all descended… from a common ancestor.” — Pinker [26:02]

On Comedy and Bonding:

• “If you get the joke, then what has just been made public is something that you privately knew all along.” — Pinker [41:37]

On Bank Runs and Virality:

• “When Roosevelt said, ‘the only thing we have to fear is fear itself,’ this was a theorem of common knowledge.” — Pinker [44:05]

On Culturally Fractured Knowledge:

• “There has been a segregation into two separate pools of common knowledge… Each one then hung out with people like them. And then the common knowledge that they shared started to grow disjoint.” — Pinker [52:25]

Cosmic Perspective:

• “You know what the hardest thing is? The human mind. …I just hope that the study of the human mind by the human mind is not the most complex thing we ever have to tackle in this universe.” — Neil deGrasse Tyson [57:53]

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Important Timestamps

• 01:56 — Introduction to topic: Why is “common knowledge” interesting?
• 05:19 — Pinker introduces his new book and defines common knowledge.
• 07:40 — Common knowledge as the foundation of civilization.
• 09:00 — Schelling’s “meeting in Manhattan” example.
• 15:28 — “Acceptable duplicity” and plausible deniability in social interactions.
• 25:04 — Laughter, blushing, crying, eye contact as generators of common knowledge.
• 28:29 — Eye contact, social norms, and threat signals across primates.
• 41:37 — Comedy and the bonding power of shared knowledge.
• 44:02 — Virulence and bank runs: When rumors go viral.
• 47:16 — Johnny Carson, toilet paper shortages, and the power of public jokes.
• 50:31 — Trump, norm-breaking, and the fragility of social expectations.
• 51:05 — The fracturing of national common knowledge and the rise of polarization.
• 55:18 — Hope for civil disagreement: mathematical models and epistemic humility.
• 57:53 — Neil’s cosmic perspective on the complexity of the human mind.

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Tone and Style

The episode is lively, humorous, and intellectually accessible, marked by the playful banter between Tyson, Nice, and Pinker. Listeners are treated both to insightful science and relatable, sometimes irreverent, pop culture references—everything from “Coming to America” and “Friends” to national political events and viral behavioral panics.

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Summary Takeaways

• Common knowledge—not just what is known, but what is publicly known to be known—is fundamental to society’s functioning.
• It shapes money, power, relationships, language, and humor, and underlines everything from institutional power to viral fads.
• The move from private to public knowledge can upend hierarchies, spark mass behaviors, or mend/break social bonds.
• Comedy, education, and even basic conversation are all built on shared common knowledge.
• The fracturing of common knowledge threatens social cohesion, but attending to civil discourse and humility in argument offers hope.

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Final Quote (Pinker, 57:07):

“That would be the kind of norm, it goes against human nature... But for that norm to spread in journalism, in politics, in the court system would be a good thing. It would be transformative. Yes. More truth, less vituperation.”

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Steven Pinker’s latest book:
When Everyone Knows that Everyone Knows: Common Knowledge and the Mysteries of Money, Power, And Everyday Life

Transcript

[Neil deGrasse Tyson]

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[Gary]

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[Neil deGrasse Tyson]

Finally got Steven Pinker.

[Gary]

I know.

[Chuck Nice]

Okay, yes. We're gonna learn all about how the brain is messed up.

[Neil deGrasse Tyson]

We don't need him for that.

[Chuck Nice]

Coming up, the latest from the mind of Steven Pinker on StarTalk. Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk Special Edition. Neil Degrasse Tyson here, your personal astrophysicist. And when you hear special edition, that means we have Gary in the house.

[Gary]

Hey, Neil.

[Chuck Nice]

How you doing, Gary? I'm good, Chucky, baby.

[Neil deGrasse Tyson]

That's right.

[Chuck Nice]

How you doing, man?

[Neil deGrasse Tyson]

I'm doing great.

[Chuck Nice]

So today we're talking about common knowledge. Yes, common knowledge. But why is that interesting?

[Gary]

If we think about it, we humans have evolved to be social creatures. And we rely upon each other for many things. We use language to communicate and coordinate ourselves. But do we consciously strategize in our social behavior? And are we aware of our own signaling when we interact? And to your point, what role does common knowledge play in our everyday lives?

[Chuck Nice]

I depend on that all the time, just as an educator.

[Gary]

Fine. But a lot of people won't realize that it is something they're using as a tool. Some people will, as you do. And does it then play a role in the big ticket items like financial crashes or political revolutions? Now? Okay, I can drone on. I've said enough. Let's introduce our guest.

[Chuck Nice]

We're gonna connect common knowledge to revolutions.

[Gary]

Let's see.

[Steven Pinker]

Okay.

[Chuck Nice]

Okay. We've got the world's expert on that topic.

[Neil deGrasse Tyson]

Yes.

[Chuck Nice]

Sitting right here.

[Neil deGrasse Tyson]

Well, thanks, guys. I appreciate that. You know I've never pan left.

[Chuck Nice]

Steven Pinker.

[Neil deGrasse Tyson]

We met.

[Gary]

Steven.

[Chuck Nice]

Steven pinker. Welcome to StarTalk.

[Steven Pinker]

Thank you.

[Chuck Nice]

My gosh, we go way back. We do decades. This, I think, is your first time on StarTalk. Bad oversight on our part because there's no reason for that. You're too active. You're too. Your stuff you work on is too interesting for it to have gone this long without you being on. So thank you.

[Steven Pinker]

Better late.

[Chuck Nice]

And I just have to ask up top, are you still winning the Best Hair for Scientist contest? Every year.

[Steven Pinker]

Oh, I don't know if the Luxuriant Flowing Hair Club for Scientists is still active, but I was.

[Chuck Nice]

That's what it was called.

[Steven Pinker]

Luxuriant Flowing Haircut Scientist.

[Chuck Nice]

That means it had no black people in it.

[Steven Pinker]

I think it did, actually. I mean, there are. I mean, there's some impressive threadbacks.

[Chuck Nice]

Oh, dread. You can dread your weight.

[Neil deGrasse Tyson]

There's some pretty amazing Afros out there too.

[Chuck Nice]

Okay.

[Steven Pinker]

Okay.

[Gary]

It's a pretty cool club.

[Steven Pinker]

This is a project of the respected scientific outlet, the Journal of Irreproducible Results.

[Chuck Nice]

Oh, good. Okay. We should do a whole episode on them at one point.

[Steven Pinker]

And the IG Nobel Prizes. I've never won one. I'm.

[Neil deGrasse Tyson]

That's great.

[Chuck Nice]

So you are cognitive psychologist, I think that's what they call you. Do I remember you being a linguist, though? Long ago.

[Steven Pinker]

I'm not a professional.

[Chuck Nice]

Not a. But that was your.

[Steven Pinker]

I'm a psycholinguist, which is the psychology of language, which is a branch of cognitive psychology.

[Chuck Nice]

That's how I first met you and knew your work.

[Steven Pinker]

But for me, language is just one of the amazing things the human mind does. So I don't have a PhD in linguistics, but in cognitive psychology.

[Chuck Nice]

Got it. Got it. And I have got you here as the John Stone family professor of psychology at Harvard University. So are you in the famous the Psychology building there?

[Steven Pinker]

William James Hall, a 15 story white building sticking out like a sore thumb in a Cambridge residential neighborhood.

[Chuck Nice]

I got you down here for a dozen books. Several of them are some of my favorite books. You know, the Blank Slate, which had its own bit of controversy, but it was fun to see an intelligent argument presented into that space. The better angels of our nature. Oh, my gosh. It has the two words common knowledge in the title, in the subtitle. Subtitle. So give me the full title.

[Steven Pinker]

So the title of the book is When Everyone Knows that Everyone Knows. And there's a story behind that. The subtitle is Common Knowledge and the Mysteries of Money, Power And Everyday Life.

[Neil deGrasse Tyson]

Whoa.

[Steven Pinker]

And I can explain all of those things.

[Chuck Nice]

Leave anything out there.

[Neil deGrasse Tyson]

That is. That's a title. That's actually three titles.

[Steven Pinker]

You see what he does?

[Gary]

I mean, I know you're a psychologist, but you've put in mysteries.

[Steven Pinker]

Yes, there you go.

[Gary]

And then Money and Power.

[Steven Pinker]

I should have put in sex, too. No, no, I'm sure you'll get that.

[Chuck Nice]

You're completely manipulating the buyer. Of course.

[Steven Pinker]

Right, of course.

[Neil deGrasse Tyson]

Now, I want to hear the story behind this title, because that's a lot.

[Steven Pinker]

Okay, so common knowledge, in the technical sense refers to the situation where I know something. You know it. I know that you know it, you know that I know it. I know that you know that I know it ad infinitum. So it's when everyone knows that everyone knows. And the dot, dot, dot is essential. I had to fight with my editor. He says, oh, it'll screw up the computer listings. On. That's the Infinity.

[Chuck Nice]

Because technically, it does mean. You know. The first I saw that was Ralph Kramden in the Honeymooners.

[Neil deGrasse Tyson]

You know that I know that.

[Chuck Nice]

You know that I know. Norton.

[Neil deGrasse Tyson]

Norton.

[Steven Pinker]

Oh, my God. I didn't put that in the book.

[Neil deGrasse Tyson]

Norton. Actually, that's Eddie Murphy.

[Chuck Nice]

No, no, he's imitating.

[Neil deGrasse Tyson]

He's imitating. The actual honeymoon is right. You know that I know that.

[Chuck Nice]

I know.

[Neil deGrasse Tyson]

Norton.

[Steven Pinker]

I can't believe I left that out.

[Chuck Nice]

Yeah. That was my first encounter with the Infinity.

[Steven Pinker]

I gotta look that up of this. Yeah, yeah, yeah, yeah.

[Chuck Nice]

That epilogue, the original. Then it's definitely Eddie Murphy imitating them.

[Steven Pinker]

Just as good. That may be better. Yeah. So to be distinguished from private knowledge, where everyone knows something, but they may not know that everyone else knows it. And that makes a big difference. It does. Wow.

[Chuck Nice]

I never sought to think about that.

[Steven Pinker]

It's been explored by game theorists, the branch of mathematics dealing with the best strategy, when other people are dealing with. Have their own strategies. It's a big deal in economics for reasons that we'll get to. It's been studied by philosophers, but it is a psychological phenomenon. It's getting in the heads of other people when they're getting into your heads or still other people's heads. And they've never been explored from a psychological point of view. Now, why is this significant? The reason that it's important is that common knowledge is necessary for coordination. That is for two people being on the same page, doing things that benefit them both, as long as each one can expect the other one to do it. And expect.

[Chuck Nice]

Don't we call that civilization?

[Steven Pinker]

Well, civilization does depend on common knowledge, on institutions like government, like money. The reason it's in the subtitle is the only reason that a piece of paper with Abraham Lincoln on it is valuable is because other people treat it as valuable. Now, why do they treat it as valuable? Well, because they know that other people will treat it as valuable. That's what makes it a currency. Likewise for power. There's no way a government can intimidate every last member of its citizenry.

[Neil deGrasse Tyson]

Give it time. I'm working on it.

[Steven Pinker]

I recognize the impression. But the government has power. A president is a president and a governor is a governor, and the chairman of the board is the chairman of the board because everyone treats them as if they are. It's a social reality. Our corporations, our religions, our gods, our conventions, even language itself. What makes the word rose refer to a rose? It would smell as just as sweet. By any other name, rose means rose, because everyone knows it means rose. And everyone knows that everyone knows. So all of our conventions, all of our ways of coordinating, all of our harmony depends on common knowledge. Just to give a concrete example from Thomas Schelling, the political scientist and economist who was one of the originators of the concept, imagine that, say, a husband and wife get lost in Manhattan. This is the era before cell phones. How can they meet up? He can think, well, she likes to go to a bookstore, so I'll meet her there. But then he thinks, oh, but she knows that I like to go to a camera store, so maybe she'll go to the camera store. But then she knows that I know that she likes to go to the bookstore, so she'll go to the bookstore after all. Meanwhile, each of them can kind of ricochet with this useless empathy and still not end up at the same place at the same time. Nothing short of common knowledge, not only knowing something, but knowing that the other person knows that you know, gets them together. Now, common knowledge can be generated by language. And that's how I got into it. That is, you know, in this case, a cell phone call. Although it can also just be a convention, something that everyone assumes that just coordinates everyone. Like, what day of the week do you stay home? Sunday. Why Sunday? Well, because everyone else stays home on Sunday. So that's a good reason for me to do it if everyone else is doing it. So a lot of our society depends on common knowledge. This immediately raises a question. People say, well, you define common knowledge as, I know that she knows that I know that she knows that I know that she knows. But no one can Keep track of them. That's why you have plots like the Honeymooners or there's an episode in Friends that people always tell me about where Rachel says, joey, they don't know that we know that we know they know that we know. You can't say anything. And he says, I couldn't even if I wanted to. The point being that your head starts to spin when you have to keep track of more than two or three layers of I know that she knows. So how is this possible? Well, the reason it's possible is that we can get common knowledge at a stroke when there is something that we sense to be public or out there or salient or you can't miss it, or it's in your face. So if I see something at the same time as I see you see it then that implicitly packs into it as many layers as we would ever need and we don't have to think them all through. But it also means that we're really, really sensitive to something that is public that you can't ignore versus something that may be known privately. And I have chapters in the book on how that shapes our language. Why we don't just blurt out what we mean but often veil our intentions in euphemism and innuendo to prevent things from being common knowledge. Phenomena like being in the closet or.

[Chuck Nice]

For any whatever is the reason.

[Steven Pinker]

Well, it used to be the gay people.

[Neil deGrasse Tyson]

That's where my clothes are. That's why I'm in the closet.

[Steven Pinker]

Well, my graduate.

[Chuck Nice]

That means you have a walk in closet.

[Steven Pinker]

I didn't know that.

[Chuck Nice]

Very good.

[Steven Pinker]

Well, my graduate advisor, actually, he insisted he was not gay. He was a homosexual in the day. In the day. That's right. He said that to be gay you have to be born in the 50s or later. He was born in the 20s, but no one ever acknowledged that he was gay. And he would never acknowledge it. Sometimes we described him as a bachelor.

[Neil deGrasse Tyson]

Now, each of us confirmed the bachelor.

[Steven Pinker]

Confirmed bachelor until he was in his late 50s when he finally, as we say, came out. Now, notice the metaphors. In the closet means that it's not public. You can't see it. Coming out means not only can you see him, but you can see everyone else seeing him. That's a good metaphor for common knowledge. And common knowledge in general governs our relationships as well as our institutions. So it's not just money and power. The everyday life in the subtitle comes from the fact that our relationships of deference, of intimacy, of friendship, romantic relationships, transactional relationships they all exist because both parties know they exist. What does it mean to be friends? It's not like you sign a contract.

[Chuck Nice]

It was an implicit contract. In a way, it is an implicit.

[Steven Pinker]

And it's a complex that depends on common knowledge. Namely, what does it mean for us to be friends? It means that I know that you know that we're friends and I know that you know that I know that we're friends. That's all there is to it. And so sometimes when we don't want to threaten a relationship, we might avoid common knowledge by hinting slipping in our intentions as eating around the bush euphemism. You kind of catch my drift. You connect the dots, whereas if you blurt it out, then that changed the nature of the relationship.

[Neil deGrasse Tyson]

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[Gary]

Let me try.

[Steven Pinker]

T Mobile's got home Internet. How much is it?

[Neil deGrasse Tyson]

Just 35 bucks a month and it's guaranteed for five years. Switching T Mobile's got home Internet.

[Steven Pinker]

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[Neil deGrasse Tyson]

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[Neil deGrasse Tyson]

Hey, this is Kevin the sommelier, and I support StarTalk on Patreon. You're listening to StarTalk with Neil DeGrasse Tyson. So what about those Where I'll see the common knowledge. But there is what I'll call an acceptable duplicity.

[Chuck Nice]

Yeah, a two way duplicity.

[Neil deGrasse Tyson]

A two way duplicity. Like we're both aware of it.

[Chuck Nice]

Yeah, but nobody wants to blurt it out.

[Neil deGrasse Tyson]

I don't want to upset the apple cart because what we got here is good.

[Steven Pinker]

That's exactly what I talk about. I have a chapter called Weasel Words.

[Chuck Nice]

Weasel Words, Yes.

[Steven Pinker]

That sounds like a fun chapter, but acceptable duplicity. When I mean, there's all kinds of kind of benign hypocrisy. The politician who resigns to spend more time with his family, the escort services. Would you like to come up for Netflix and Chill? Let's say you were trying to bribe a maitre d to jump the queue and be seated immediately. You might kind of holding out a $50 bill in peripheral vision. Say, is there anything you can do to shorten my wage? I was wondering if you might have a cancellation. Right.

[Chuck Nice]

You did all a cancellation and not.

[Steven Pinker]

If I give you 50. Will you seat me right away?

[Neil deGrasse Tyson]

Exactly. Because that would be crass.

[Steven Pinker]

And so what does it mean for it to be crass? What it means is you're disrespecting the relationship you have where he is the authority and he sees you where and when he pleases. You're treating him like a transactional relationship, which is a very different kind of human relationship. Interesting. Likewise, transactional. What's the difference between you want to come out for Netflix and Chill and to come up for sex? Well, with Netflix and Chill, there isn't really plausible deniability. I mean, you know, she's a grown up. She knows what it means, but she could have some doubt that you know that she knows that you know what it means. And she could think, well, maybe he thinks I'm naive and I'm just turning down an invitation to a movie. He could think, well, maybe she thinks I'm dense and that I might think she's naive or I might think that she doesn't realize that I'm not naive. And so they can maintain. Go back to their platonic relationship. They haven't jumped to plausible deniability. Well, it's a plausible deniability of common knowledge. Because when you think about it, it's really not that plausible.

[Neil deGrasse Tyson]

Right. Everybody knows.

[Steven Pinker]

But like the things that everyone may not know. That everyone knows.

[Neil deGrasse Tyson]

Exactly. And what that does is it allows you to save face.

[Steven Pinker]

So saving face, by the way, another great. Going back to the idea. How could. If common knowledge is so important, as I say it is, and it requires. I know that she knows, which makes your head hurt, how could it work so well? And one of the reasons is that we talk about it not using the language of philosophy or game theory, but metaphors of something being visible out in the open. That's why we use expressions like in the closet or saving face. Face is the part of you that other people see and that you use to see other people. So saving face or losing face is a great metaphor for knowledge.

[Chuck Nice]

The facade of your face, in a way, by saving the face that you had established prior.

[Steven Pinker]

Well, this face and facade are related.

[Chuck Nice]

Yeah, I guess. Do you know in the movie Back to the Future, there's a deleted scene, which.

[Neil deGrasse Tyson]

How could I know that?

[Chuck Nice]

Okay, sorry. Where the doc is setting up his connection to the clock in anticipation of the lightning strike.

[Neil deGrasse Tyson]

Okay.

[Chuck Nice]

And the cop comes by and says, oh, doc, what you doing? I'm just doing some weather. Give me his voice. Some weather experiments. I'm doing some weather experiments. Thank you. And then. And so then. And he said, you got a permit for that? And he says, of course I do. Okay. So then he comes down and goes up to him. This is the deleted scene. He walks up to him, opens his wallet and there's just cash there.

[Steven Pinker]

Oh, my goodness.

[Chuck Nice]

It doesn't have his permit.

[Neil deGrasse Tyson]

I didn't. Oh, I was about to see. I didn't see that.

[Chuck Nice]

So he bribed him. But that's kind of out of character with how he. He's just a lovable, doddering old, old scientist.

[Neil deGrasse Tyson]

That would have damaged his character.

[Chuck Nice]

It would have damaged the character.

[Neil deGrasse Tyson]

Yeah, that would have damaged the Character.

[Steven Pinker]

But that would have been a perfect example.

[Chuck Nice]

It's transactional.

[Steven Pinker]

Well, the thing is that it's, in fact transactional. But it's very dangerous to suggest to a cop that you have a transaction. In fact, it's illegal.

[Chuck Nice]

So he just makes it visible.

[Steven Pinker]

Exactly.

[Chuck Nice]

That's all it is.

[Steven Pinker]

So that. So there is somewhere in here. And so, you know, it's not plausibly deniable, but it's deniable that the other person knows that you know or knows that you know that he knows that you know. And that's what. That's what flips it from deference and respect and authority to transactional. And you want to avoid that flip, but you still want to do business.

[Neil deGrasse Tyson]

There was a scandal because I'm from Philly and it was, of course, Philadelphia politicians, but I forget the name of the scandal, but it was very famous because they caught it on tape and only one politician didn't go for it. But these people, these. The. These feds dressed up as, like, Saudi businessmen.

[Steven Pinker]

Oh, and they had Abscam ab Scam.

[Neil deGrasse Tyson]

That's exactly right. And they had, like, piles of money, like, in sitting out.

[Gary]

That's been done a number of times.

[Neil deGrasse Tyson]

Around the world as they were discussing what they wanted. Oh, and then only one of the politicians was just like, yeah, I'm not worried about that. Let's talk about. Everybody else went down because they.

[Chuck Nice]

It was. It was the financial seduction is what that was.

[Neil deGrasse Tyson]

But they never said, this money is yours. They just put a pile of money in front of them. And they were like, so let's talk about the new rail line.

[Steven Pinker]

Veiled bribes.

[Chuck Nice]

Veiled bribes.

[Steven Pinker]

Veiled threats.

[Neil deGrasse Tyson]

Veiled threats.

[Steven Pinker]

Like I quote an episode from the Sopranos in which a member of the family approaches a high school acquaintance, says, hey, great to see you, Danny. I hear you're on the jury for the Soprano trial. It's an important civic responsibility that we should all take part in. You've got a wife and kids. We know you'll do the right thing. That's a veiled bribe.

[Chuck Nice]

Right.

[Steven Pinker]

Now, of course, bribes, extortion is illegal, right? I mean, in everyday life, there are occasions where there are implicit veiled threats that you don't spell out in so many words because that establishes a relationship of dominance. And you may want to avoid that relationship while still getting the message.

[Chuck Nice]

That would completely change the dynamic.

[Steven Pinker]

Change the dynamic. So that's what that chapter is you asked about.

[Neil deGrasse Tyson]

That doesn't happen in the black community. It's just like, I will kick your ass.

[Chuck Nice]

It's resolved in the moment.

[Neil deGrasse Tyson]

It's resolved in the moment.

[Chuck Nice]

What?

[Neil deGrasse Tyson]

I will kick your ass. No.

[Steven Pinker]

Well, there are. I mean, so that's a case where the relationship of dominance is already established. Dominance.

[Chuck Nice]

That's the exact scene in Coming to America.

[Neil deGrasse Tyson]

Is it?

[Chuck Nice]

Where they're at the McDowell's home and the king says, how much for your daughter? Okay, this is America, Jack. You better stop me before I put my foot up your ass.

[Neil deGrasse Tyson]

Was that John Amos? I forget the example in the moment.

[Chuck Nice]

Right, because it's a king. And just like a rich American.

[Steven Pinker]

Another great example. So why do cultures differ from each other? Well, if you think of the different kinds of relationships. So the basic kinds of relationships are communal, sharing, warmth, intimacy. That's one model, not America. Well, another model is.

[Chuck Nice]

What'S mine is mine, what's yours is mine.

[Steven Pinker]

And then that's. Well, there's actually a twist on that. So another relationship is hierarchy, alpha male, pecking order, top dog. And the third one is transactional. Now, where cultures differ is not across the board, but. But in what kind of relationships? Parent, child, student, teacher, employee, boss, friend, friend. What resource, money, favors sex, and in what context? Home, school, public. If you mix and match those, that gives you kind of all the variation from Anthro101. And so there's certain resources. So for example, there are cultures that really openly trade brides or daughters to become brides. Ours doesn't commoditize that explicitly, but we do say buy and sell land, which some cultures don't do, where the land might be communal. And so if you think of all the resources, all the context, all the matrix of. That's kind of the matrix of Anthro101.

[Gary]

So if we look at common knowledge as a variant of culture, and different cultures prize certain common knowledge differently, how often do we get the misinterpretation of our common knowledge?

[Steven Pinker]

We often get misinterpretations when they're cross cultural.

[Gary]

Exactly. Yeah, exactly.

[Steven Pinker]

And that's part of what culture shock is. You don't know what is the common knowledge in the new community that you have to deal with. And that can result in war. It could result in war. I mean, it could result in misunderstandings, sometimes comical ones. And that's used in comedy, as in Coming to America, as in Borat, where you have the bumpkin from one culture using the assumptions that were native to that guy's culture but completely inappropriate, sometimes leading to embarrassment, sometimes to shock and outrage.

[Gary]

Yeah. And then if we look at the communication through body language or unintentional signaling.

[Steven Pinker]

Yeah, so there's. I have a chapter called Laughing, Crying, blushing, staring, glaring about non verbal common nouns.

[Gary]

Couldn't get a long title then.

[Steven Pinker]

Laughing, crying, blushing, blushing, staring, glaring, glaring, glaring.

[Chuck Nice]

Okay.

[Steven Pinker]

Now we have dozens, maybe hundreds of facial expressions. You know, smiling and frowning and grimacing and so on. But on top of that, we have some really conspicuous forms of nonverbal communication that have puzzled people for millennia, such as laughing. Why do we interrupt our speech with that staccato noise?

[Chuck Nice]

Yes, Stephen, why?

[Steven Pinker]

I thought you'd never ask.

[Neil deGrasse Tyson]

Chuck needs to pay his mortgage, that's why. I mean, come on.

[Chuck Nice]

I forgot there's a whole profession that depends on this.

[Steven Pinker]

Yes, yes. So what I argue is that for these conspicuous displays, blushing is another one. Why should blood go to your cheeks? Crying. Why should a fluid shed tears? Why do you shed tears? I suggest that they are common knowledge generators. So when you're laughing, you know you're laughing because your breathing is interrupted. Other people know you're laughing because they can hear it. Other people know that you know, you know that other people know, et cetera. Blushing. You feel the heat of the blood, the inside in your cheeks. Knowing that other people can see the change in color from the outside. And they know that you know that you're feeling it. All the more so when they say you're blushing.

[Neil deGrasse Tyson]

I've never had that problem.

[Chuck Nice]

Yes, it's not a black people. It's a lesser thing.

[Steven Pinker]

Okay, so maybe you can. Friends. So Darwin worried about this, because Darwin was a big proponent of universal emotions. In fact, for him, he had a.

[Chuck Nice]

Whole book on it.

[Steven Pinker]

A whole book on it. The expression of the emotions in animals and men.

[Chuck Nice]

Yes, yes.

[Steven Pinker]

And in fact, he used it, in fact, as an argument against the kind of the scientific racism of his day, which said the different races were. Were independently evolved or created, one or the other, either one. And he said that the similarity in facial expressions, in many other aspects of emotion showed that we all descended pretty recently from a common ancestor. Wow. And his data, I mean, he was kind of an invalid, but he corresponded with colonial officers and missionaries and traders all over the world, and he had them, he gave them questionnaires to ask of their interactions with local people, which they then mailed back to him.

[Chuck Nice]

So just to be in context, this is before photography could capture it. Right. I'm just at the dawn of photography.

[Steven Pinker]

What that is, in fact. Well, his book, this book that we're talking about, was the first use of scientific photography, although not for cross cultural studies, because the missionaries didn't have canvas out there in the field, but he actually used it to analyze the musculature in facial expressions, including studies where they got a person in an asylum and they shocked the different muscles to see what they did to a facial expression.

[Neil deGrasse Tyson]

Wow.

[Steven Pinker]

That was a bit of a digression. Going back to the question though, of.

[Chuck Nice]

Asylums, all they ever use is electricity on you.

[Steven Pinker]

That's what it seems like. But he asked the question, do dark skinned people blush and is it detectable? And at least the answer from him and the answer that I got from Nina Jablonski, who's an expert on skin color, is yes, it may not be.

[Chuck Nice]

Well, I'm not denying it. I'm just saying it's not an active referent in our comments of people's emotions.

[Steven Pinker]

But I even cite a Ghanaian physician.

[Chuck Nice]

Ghana, Ghanaian, yes.

[Steven Pinker]

Very dark skinned. Who said, well, my mother can tell when I'm blushing. It's a change in color. Anyway, the point is that it's a common knowledge generator in that you know that you're experiencing it. You know that other people can see you experiencing it. They know that you know you're experiencing it. Tears. You're looking at the world through a scrim of fluid. It blurs your vision at the same time that other people can see the glistening or the trickle. So again, you know that you're crying. Other people know that you know that they know. And eye contact is the ultimate common knowledge generator because you're looking at the part of the person that's looking at the part of you that's looking at the part of them that's looking at the part of you ad infinitum.

[Chuck Nice]

Here we go again.

[Steven Pinker]

You don't have to think about it ad infinitum.

[Chuck Nice]

But what about this eyebrow thing? Why should that mean anything other than what it means?

[Steven Pinker]

Well, Darwin dealt with that in the book where he noted that some facial expressions are vestiges or remnants of facial postures that animals do when they're about to attack or they're defending themselves. So in the case of the fear expression, he noted that if you're likely to be a prey animal or someone who's going to be picked on by the alpha, you've got to open your eyes wide to see where threats might be coming from. If, on the other hand, you're the predator or you're the alpha, you want to focus. Exactly. And if you. The remnants of that include. And so the furrowing your brows, which I think narrows the field of vision, that may Even narrow, if the folds of skin actually intrude on the pupils, might increase depth of field.

[Chuck Nice]

Yes, it does.

[Steven Pinker]

That is optically.

[Chuck Nice]

Optically. That's why people, if they don't have their glasses on, they squint and. They squint.

[Steven Pinker]

They squint, exactly.

[Chuck Nice]

They don't even know that they're increasing their depth of field by doing so. I mean, they're not actively thinking it. They just know they see better.

[Steven Pinker]

Going back to these nonverbal common knowledge generators, we use them to make something public that formerly was private. That's the common denominator.

[Neil deGrasse Tyson]

Yes.

[Steven Pinker]

So in the case of eye contact, now that developed way before we were humans, because among primates, eye contact is a threat signal. The dominant stares at the subordinate who looks away, which is, by the way, also true in humans.

[Gary]

The bosses don't make eye contact. People walk with their head down.

[Neil deGrasse Tyson]

That was the first thing I was told when I came to New York City as a kid. We were on the subway and they said, whatever you do, do not make eye contact.

[Steven Pinker]

I said, you looking at me, right? Who you looking at? I had a young person walked past.

[Gary]

Me yesterday evening, and I'm thinking, if you don't look up, you are going to walk into me. And it was intentional not to make any eye contact.

[Steven Pinker]

Well, the anthropologist Herv Devore used to tell his class, if two human beings look into each other's eyes anywhere on Earth for more than six seconds, then either they're going to have sex or one of them is going to kill the other one.

[Chuck Nice]

That is so true. There you go.

[Steven Pinker]

Oh, my gosh, what a great saying.

[Chuck Nice]

That is true.

[Steven Pinker]

It's true.

[Neil deGrasse Tyson]

So why is this so uncomfortable? I mean, even, like, I don't mind making eye contact, especially if the person's decent looking. Like, I've got to tell you, when somebody's unattractive, I'm. It's tough.

[Steven Pinker]

Yeah.

[Neil deGrasse Tyson]

I'm just saying it is rough to look at somebody who is not attractive and, like, maintain eye contact, but prolonged eye contact. And I don't know if it's just me, but I'm just gonna put it out there. I'm gonna be honest. It gets a little, like, creepy and uncomfortable.

[Steven Pinker]

Oh, it absolutely does. Okay, so. And I actually write about this. So what we call eye contact in ordinary conversation is it's a bit of a misnomer. Your eyes kind of dance all over the face all the time. You spend a lot of time lip reading, but it's the eyeball to eyeball stare that's really which is something different. Now we're humans, we're not, you know, we're not monkeys, we're not gorillas. And so eye contact doesn't have one meaning. I mean, it can be seduction, it can be threat, but more generally it can be something that formerly was private knowledge is, as of this moment, common knowledge. Which is why we say things like, can you look me in the eye and say that that's great, tell me the truth?

[Gary]

Basically, we're trying to interpret so many different things and that's why you get uncomfortable.

[Steven Pinker]

And when you're embarrassed, you look down, you look away, you avoid making eye contact. So what laughter does is it makes what used to be private knowledge common knowledge, where it's some indignity or infirmity or weakness of some. But of the joke. Now that can be someone that you're trying to bring down. It could be someone you're trying to keep down in aggressive humor. Although it can also. There's also of course, convivial humor. What we've all been doing, where the signaling is to reinforce the egalitarianism that's the basis of warmth and friendship. Because there's always a danger of a dominance creeping in. With any two people, one of them is going to be better looking, smarter, richer, more powerful. But that's not what you want to do in your friends. When you're friends, it's like we are all on the same level. And so by calling attention to some weakness in yourself that you could lord over people, but you don't want to lord over people, or vice versa, gentle teasing and joshing that the other person accepts, then you're re establishing the common knowledge that the basis of our relationship is self depreciation. Yes, exactly.

[Chuck Nice]

So what does one do for. Is it whatever the number is? Is it 1 out of 10 or 1 out of 6 of us? Who's on the spectrum where social cues do not play?

[Neil deGrasse Tyson]

Exactly.

[Chuck Nice]

Might that be adaptive where now you don't know anything about me because my facial expressions are not responding and therefore I'm not revealing my inner secrets to you.

[Steven Pinker]

Well, there is the.

[Chuck Nice]

That could have survival value.

[Steven Pinker]

I suspect that's more likely used strategically, as in the poker face. That is the poker face where you deliberately hide the tells. In a case where you're not in a situation of cooperation but zero sum competition, then any kind of tell could be used to your disadvantage. So you people.

[Neil deGrasse Tyson]

I don't play poker because I'm the worst. It's just. Damn.

[Steven Pinker]

Oh, just kidding.

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[Gary]

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[Steven Pinker]

Hey, Sal.

[Gary]

Hank.

[Steven Pinker]

What's going on?

[Gary]

We haven't worked a case in years.

[Steven Pinker]

I just bought my car at Carvana and it was so easy.

[Neil deGrasse Tyson]

Too easy.

[Gary]

Think something's up?

[Steven Pinker]

You tell me. They got thousands of of options, found a great car at a great price.

[Neil deGrasse Tyson]

And it got delivered the next day.

[Steven Pinker]

It sounds like Carvana just makes it easy to buy your car, Hank. Yeah, you're right. Case closed.

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[Gary]

All right. To go back briefly to the animal theme.

[Steven Pinker]

Yeah.

[Gary]

What about the elephant in the room? You know, the Emperor's New Clothes scenario?

[Steven Pinker]

So the. I actually opened the book with the Emperor's new Clothes because that's a story about common knowledge.

[Gary]

Yes.

[Steven Pinker]

When the little boy said the the emperor was naked, he wasn't telling anyone. They didn't anything they didn't already know. But he was changing their knowledge because when he blurted it out in public, now everyone knew that everyone else knew that everyone else knew. So he converted private knowledge to common knowledge. So first of all, that made a difference. That's the you Know the climax of the story, what it is. It changed their relationship with the emperor from deference to ridicule and scorn. So a relationship went to the emperor or to the. To the emperor?

[Chuck Nice]

To the tailor.

[Steven Pinker]

Well, but to the emperor too. At least in the.

[Chuck Nice]

No, the tailor. But the tailor fooled him. It's the tailor's fault. It's not the emperor's fault.

[Neil deGrasse Tyson]

Which is why I'm gonna have him killed right away as if he was clinging to a boat.

[Chuck Nice]

Did I have a Disneyfied version of that story? I mean, the tailor is the one who should be.

[Steven Pinker]

Yes, but at that moment, in public, it was.

[Neil deGrasse Tyson]

The emperor suffers all of the embarrassment.

[Steven Pinker]

Especially in the. The Danny K version of the story, where it was met with ridicule and scorn in the lyrics to the song.

[Chuck Nice]

Okay.

[Steven Pinker]

And deference is a matter of common knowledge. You defer to someone because you know they'll stand their ground. Why do they stand their ground? Because they know that you'll defer to them. Why do you. And how do they know that? Well, because you know that they know that they'll stand their ground ad infinitum.

[Neil deGrasse Tyson]

And what about the mutuality of respect? I mean, that's the flip side of that. Sometimes there's a matter of deference because you truly respect the person. They understand that you truly respect them, and they respect that. You know.

[Steven Pinker]

Yeah. There are different flavors of the hierarchical relationship. It could be dominance, which basically means, you know, I could hurt you if I wanted to. There can be status. I could help you if I wanted to. There can be expertise. You all have a common interest in the decisions being made by someone who knows what they're talking about. Or even sometimes if everyone's going. And the expression herding cats. Even if no one has a particular reason to be the decider, it's best for everyone if there is a decider. And that can give you a hierarchical relationship. But we do use metaphors, like saving face out there. And the elephant in the room is obviously something that everyone can see. And.

[Chuck Nice]

So the elephant in the room is the emperor's new clothes. Because no one is talking about it.

[Steven Pinker]

That's right.

[Chuck Nice]

Even though everyone knows that it's there.

[Neil deGrasse Tyson]

Which is why the saying always is, let's acknowledge the elephant in the room. In other words, like, we all see it. Now, let's talk about listening to you.

[Gary]

So far, I get the feeling that there's a kind of a logic to common knowledge and maybe even like a code. And that might then culturally vary.

[Steven Pinker]

Yes. So I think the phenomenon of common knowledge and things that generate it, like blunt speech, like eye contact, is universal. But then what are the relationships that are negotiated with common knowledge or ratified by common knowledge? That is, what can friends share? What can a boss demand of an employee? How is sex treated? Can it be transactional, or is it only intimate? All of these mixing and matching of resources, relationship models and context, that's what makes cultures differ from one another. But in each case, there is some kind of common knowledge that holds the relationship in place, that sets out what you're allowed to exchange, what you're allowed to hoard, what you're allowed to demand. And that's what it means to be a competent member of a culture, to master that. Each one of them being a matter of common knowledge.

[Chuck Nice]

So, Stephen, I try to know what is common knowledge so that I can access it as an educator, I can tap it into it, I can add to it, because I don't have to train people to know things that represent common knowledge. Comedians, your joke does not work unless everybody knows what you're talking about.

[Neil deGrasse Tyson]

The more universal, the better. And by universal I mean you mean earth.

[Chuck Nice]

I'm sorry, I'm an astrophysicist here. Correct yourself. Okay.

[Neil deGrasse Tyson]

The more commonly accepted, the better earthworm, right? The more. The more earth wide, the better. But really it's about experiential knowledge. If I. Even if you've never been through what I am talking about, if I can put you there, then you will laugh with me. There are many people, many comedians that talk about marriage. And people who are single laugh because they have observed somebody else in a relationship. That they understand what this comedian is talking about.

[Chuck Nice]

That broadens your access points to the person.

[Neil deGrasse Tyson]

For instance, when Stephen was talking about the lost couple and the woman was going to a bookstore and the man was going to a camera shop, the first thing that popped into my head was, well, listen, if you know what's good for you, you better go to that damn bookstore. Because every husband knows that if I don't show up at the book store, I'm in trouble, okay? And that's the first thing that popped into my head.

[Steven Pinker]

This is an important point, because what humor often does is it establishes common knowledge. That is, if you get the joke, then what has just been made public is something that you privately knew along. And so you get that feeling of solidarity with the other person. If you're laughing at the same thing, then what was unstated, that makes the joke funny is something that you have in common. That's why Humor is such an important bonding agent for in dating. One of the main criteria in accepting.

[Chuck Nice]

A mate is sense of humor.

[Steven Pinker]

Sense of humor.

[Chuck Nice]

I haven't thought deeply about that fact. I just thought it'd just be more entertaining. But it's more bonding.

[Steven Pinker]

What it means is that you share a lot of common ground, common knowledge. That is, you can't get the joke unless there is some hidden, unstated premise that makes it work and that can bond people. It can also be a devastating put down and an intolerable insult. I give the famous example of the roast at the National Press Correspondent's Dinner during the Obama presidency, where Donald Trump was in the audience and Obama made a number of jokes at Trump's expense. Ordinarily, people are expected to be a good sport and to accept the barbs showing that they have commonality, common ground with everyone in the room. But Trump took it personally. He was visibly fuming and scowling at a joke like, well, it would be good if Donald Trump was president because he could accomplish things like closing Guantanamo, because he has a history of running waterfront real estate into the ground.

[Neil deGrasse Tyson]

That's a great joke.

[Steven Pinker]

Trump didn't think so.

[Neil deGrasse Tyson]

No, it's a terrible joke.

[Steven Pinker]

But the point is that everyone who laughed first of all knew that Trump, despite his boasts of being a business genius, had a string of failures, which made it all the more painful for Trump for that to be brought out into the open. According to some stories, that's what led.

[Chuck Nice]

Him to run in the first place.

[Steven Pinker]

Yeah, for revenge.

[Neil deGrasse Tyson]

And they're all now being investigated by my Justice Department. It was a hoax. Obama and his jokes.

[Gary]

So what about what happens when the humorist just twists the common knowledge? And I think you've got. You touched this in the book. Toilet paper shortage.

[Lowe's Advertisement Voice]

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[Gary]

And the origin of that story.

[Steven Pinker]

So there's some viral fads and phenomena which can be really significant.

[Gary]

So common knowledge is a kind of virulent property.

[Steven Pinker]

It can be, yes, exactly. So in the case of, say, a bank run where a rumor starts that the bank might be in trouble. Now, of course, banks don't have enough cash on hand to redeem all their deposits, but if you worry that other people worry that still other people worry that other people worry that the bank might be insolvent, then everyone rushes to the bank to withdraw their savings, which can actually cause the bank to fail, even if it was sound. And that can bring down an entire economy. That was in part the cause of the Great Depression. And so when Roosevelt said, the only thing we have to Fear is fear it itself. This was a theorem of common knowledge. It wasn't just a feel good bromide. But he was accurately diagnosing the situation, which is why financial leaders.

[Chuck Nice]

That's Roosevelt speaking to flat Earthers. The only thing we have to sphere is sphere itself.

[Neil deGrasse Tyson]

Oh, God, how long have you been waiting for that? No, that's a good one.

[Chuck Nice]

Is sphere.

[Neil deGrasse Tyson]

It's so bad I'm laughing.

[Chuck Nice]

It's good.

[Gary]

Oh dear.

[Chuck Nice]

It's totally good.

[Gary]

You got your dad joke out, haven't you?

[Chuck Nice]

That was a dad joke. And of course the run on the bank.

[Neil deGrasse Tyson]

It got me though, I gotta say.

[Chuck Nice]

The run on the bank in Mary Poppins was caused by a little child.

[Gary]

Yes.

[Chuck Nice]

Where they took his coin. He had some kind of pence or something.

[Gary]

A shilling.

[Chuck Nice]

Yeah. To start an account. But the boy didn't want him to do that. Said give me back my money. And then this permeated the halls of the thing.

[Gary]

Two older ladies overhear the conversation.

[Chuck Nice]

Overhear. And then it starts, oh, they're not giving him his money. I want my money. And then there's a run on the bank.

[Neil deGrasse Tyson]

That's so funny. That's great.

[Steven Pinker]

Once again, something that is public can then set off cycles of thinking about what other people are thinking about, what other people think about.

[Chuck Nice]

That's the virulence you're talking about because.

[Steven Pinker]

It just fires through. And a similar phenomenon might be why there was a toilet paper shortage during the COVID pandemic. It actually wasn't a toilet paper shortage until people thought there was this toilet paper shortage hoarded because they thought other people were hoarding. When stores started posting maximum three rolls per customer, that didn't so much throttle the demand as it reassured everyone that.

[Neil deGrasse Tyson]

There was a shortage.

[Steven Pinker]

Well, that other people wouldn't be able to strip the shelves bare. So they didn't have to worry about stripping the shelves bare. I only need three rolls, but I'm only going to ask for three rolls because none of the other people can buy more than three rolls either.

[Neil deGrasse Tyson]

Right.

[Steven Pinker]

And so that kind of.

[Neil deGrasse Tyson]

It's a level setter who is the originator of this, by the way, I still have toilet paper from the pandemic. I hate to admit it.

[Steven Pinker]

According to one story, it came from a big common knowledge generator in the day, namely Johnny Carson on the Tonight Show. So in the old era of three networks, Johnny Carson was the king of late night. He hosted the Tonight show for many decades. When you were watching it, you had a good reason to think that rest of the country was watching it and knew that the rest of the country was watching it. In the early 70s, after the oil embargo, when there was an oil shortage, he made the joke one night, you know, we have shortages of everything these days. There's shortage of gasoline, there's shortage of meat, shortage of coffee. But did you hear the latest? I read in the papers there's a shortage of toilet paper. Now it turns out there wasn't a shortage of toilet paper.

[Chuck Nice]

It was just a joke.

[Steven Pinker]

But as soon as he made the joke, there was a shortage of toilet paper as everyone started to hoard toilet paper.

[Gary]

So fulfilling.

[Steven Pinker]

And according to at least one theory, ever since then, whenever there is a hurricane or a blizzard, people think that toilet paper is the thing you gotta stock up on. Cause everyone else is gonna.

[Chuck Nice]

There's an episode of Curb youb Enthusiasm where someone was revealed to have an entire closet full of toilet paper.

[Steven Pinker]

Oh yes, during the pandemic. Yeah.

[Chuck Nice]

Yes, that's right, an entire closet. But how much ass wiping do you think you need to do?

[Neil deGrasse Tyson]

How big is your ass, by the way? In a hurricane, when your home floods, that toilet paper is not going to be worth anything. Really isn't so much fun. I'm saying.

[Steven Pinker]

Well, in the other direction, you can also get speculative bubbles. You buy crypto because you think other people are buying crypto. Or at least we'll want to buy crypto tomorrow. So they'll pay for more for it tomorrow than you pay today. They're buying it tomorrow because I think they'll sell it to someone who wants to buy it the day after tomorrow. The hot potato plate. The hot potato, yes. Or the greater fool.

[Neil deGrasse Tyson]

The greater fool.

[Steven Pinker]

And that goes back to John Maynard Keynes, who in the 1920s compared speculative investing. So this is investing not because of the return that you expect on the asset, that is the profits that the manufacturer will make selling widgets or the farmer selling food. But you think you can unload the security at a profit on someone else. And he said it's like a beauty contest where instead of picking the prettiest face, the object is to pick the face that the most other people pick. Where they're picking the face with the same goal that is trying to figure out what everyone else is picking. So sometimes called a Keynesian beauty contest.

[Gary]

Don't we have that in primaries elections?

[Steven Pinker]

And in elections are Keynesian beauty contests, that is in a primary election where there might be a field of a dozen candidates and no one wants to waste their vote in just deciding who's going to come in at seventh place as well, opposed to H, which is.

[Chuck Nice]

What ranked choice voting is trying to resolve.

[Steven Pinker]

Yes, that's exactly what it's trying to resolve. And so people are hyper aware for any signs that someone has momentum, that they're in the lead because they want to vote to determine who comes in first, not who comes in sixth. Right.

[Neil deGrasse Tyson]

I don't want to waste a vote.

[Steven Pinker]

I don't want to waste a vote. And so during the coverage, any various trivial gaffes and lapses or boosts can sometimes shoot candidates to the top or sink their candidates candidacy. Like when a few years ago when Howard Dean was running for. And that. And everyone knew you, you can't vote for Dean now because he, his victory scream means that everyone knew that he had a silly victory scream and that that ended his.

[Neil deGrasse Tyson]

Can you imagine?

[Lowe's Advertisement Voice]

Seriously?

[Neil deGrasse Tyson]

No, I'm.

[Chuck Nice]

Yes. Don't make fun of us weird politics yourself.

[Neil deGrasse Tyson]

I know qualified candidate who was not able to continue his candidacy because he was like, and then we're going to go to New Hampshire and then we're going to go to Vermont and then we're going to go to. And. And he did that. And everybody was like, oh dude, you can't be president. Not like acting like that. And then years later we're just like, you know, you can grab him by, you can grab him by the.

[Steven Pinker]

Whatever.

[Neil deGrasse Tyson]

You can just grab them anywhere you want. And they, they sometimes like you do it because you. And we're like, yeah, that's the guy. That's the guy right there. We gotta let that guy.

[Gary]

All right, moving on.

[Steven Pinker]

The Trump phenomena is interesting because what he did is done repeatedly is that he has floated norms that everyone thought were inviolable. They were inviolable only because people thought they were inviolable.

[AI Voice]

Exactly.

[Steven Pinker]

And they existed as common expectation, common knowledge. And as soon as he flouted them and did not pay the price, they no longer existed as norms. Which is why they're, I think, being copied by people like Elon Musk, also a troll, a liar, a braggart, that things that would be unthinkable for a president, for a CEO, as soon as they're thinkable, they're thinkable.

[Gary]

So is this the fracturing of common knowledge that is partly behind the polarity of society right now, where people are just refusing and disinterested mainly to find a common ground?

[Steven Pinker]

Yeah. So common knowledge always is defined relative to a network of sharing of information. It could be two people in some of the examples we've discussed, it could be the Entire country. And there has been a segregation into two separate pools of common knowledge. Everyone blames social media. That probably has something to do with it, But I think it's also cable news. Fox News, prior to social media had that effect. You weren't watching Walter Cronkite at the same time as everyone else was watching Walter Cronkite or Johnny Carson. And residential segregation, when you had educated people flocking to cities, leaving behind the less educated, when you had a decline in organizations that brought people together across the socioeconomic divides, like the army in the era of the draft, like churches, like service organizations, like, you know, the Lions Club, like bowling clubs, you stopped rubbing shoulders with people from different social classes. Each one then hung out with people like them. And then the common knowledge that they shared started to grow. Disjoint.

[Chuck Nice]

So it feeds divisiveness because, I mean, it's the same issue, as you said, multiculturally.

[Neil deGrasse Tyson]

Right.

[Chuck Nice]

Except now it's within the same culture. But now people dividing with the same motive.

[Steven Pinker]

Different cultures within the same country.

[Chuck Nice]

Within the same country.

[Steven Pinker]

Yeah.

[Neil deGrasse Tyson]

That makes me feel like it's exacerbated by what I'll call the vituperative disposition of leadership right now.

[Chuck Nice]

So I don't know what that word means. I'm sorry, what does that word mean? Vituperative?

[Neil deGrasse Tyson]

Vituperative. It means, like very Sat is.

[Steven Pinker]

Means.

[Neil deGrasse Tyson]

Like mean and nasty, like a diaper. So when we're siloed into these different camps like this, it becomes very easy then to point fingers and say, that's your enemy, that's your enemy, that's your enemy. And then it's okay to be mean and nasty towards those people. And it seems like that's exactly where we are.

[Chuck Nice]

Nazi Germany took that all the way through.

[Neil deGrasse Tyson]

I wasn't even thinking along those lines. But absolutely, yes, that's how it went down.

[Steven Pinker]

But yeah, norms of civility, things you just don't say you don't. You might disagree with someone you might even not think highly of, but you don't insult them to their face. I mean, you do on the playground, but there was a norm in politics, in corporations, in the media, that you pretend that you like them even if you don't. And those are some of the norms that are shattered. You don't lie blatantly. Now, everyone lies somewhat. Just all of us probably tell two lies a day, but you don't blatantly lie. You don't show a contempt for the truth. You at least try to pretend that you're honest.

[Chuck Nice]

Can I give an example. So I befriended a. I have a sort of Republican confidant who was in Congress for like 25 years.

[Neil deGrasse Tyson]

You can tell them that it's me, Neil.

[Chuck Nice]

He was in through Reagan and beyond. And then I was talking to Al Gore and I was saying I was friends with this guy, but I had to work it because we come from different places. And you know what he said? He didn't say anything bad. He just said, yeah, he's an acquired taste. That was pretty politic.

[Neil deGrasse Tyson]

That is a very politician.

[Chuck Nice]

Right. He didn't insult. He just said, you know, you gotta work it. And then. As any acquired taste would be. So that's an example. You don't hear that today.

[Steven Pinker]

Yeah, People are just like when Winston Churchill was asked, maybe the reason you lost the election to Clement Attlee is that people thought that Attlee was more modest. He said, well, Mr. Attlee has much to be modest about.

[Gary]

He did have a good turn of phrase. Let me ask you before we have to wrap this up.

[Neil deGrasse Tyson]

Yeah.

[Chuck Nice]

We gotta start wrapping what plays out.

[Gary]

If society remains unchecked, where the common knowledge is distorted or the common knowledge is dictated by the loudest voice, no matter what that voice is saying.

[Chuck Nice]

Yeah. By nefarious forces influencing.

[Steven Pinker]

Yeah. Well, we're seeing some of it. We're seeing the polarization, particularly the negative polarization, that is not just disagreeing, but thinking that the other side is stupid or evil. I don't have an algorithm for reversing that. But the kind of norms that we should spread would be ones of civil disagreement, epistemic humility, charity, things that go against human nature, where we tend to think of argument as a competition, as a war. I attacked his arguments, he defended them, but then I demolished them. We used the metaphors of war in talking about argument. And in one of the chapters, I talk about a different model for argument coming out of a mathematical theorem, claiming that we rational agents should not agree to disagree.

[Chuck Nice]

That's how I feel, by the way.

[Steven Pinker]

Well, there's actually some. It's a proof by the Israeli mathematician Robert Alman that depends on common knowledge. We don't have time to go through it now, but it does set a kind of an alternative paradigm for argument that instead of two people beating each other up and the one left standing wins. That's not how you discover the truth, or even bargaining and negotiating, and you come to some compromise, you think about, why should the truth just happen to lie halfway in between two opinionated guys? But rather, it's kind of a random walk where when two people exchange information, they might go all over the map until they converge on a common conclusion.

[Chuck Nice]

That's precisely how I feel. I mean, otherwise you just.

[Neil deGrasse Tyson]

Well, you would. As a scientist.

[Chuck Nice]

Yes.

[Neil deGrasse Tyson]

That is kind of like your whole field.

[Chuck Nice]

If we disagree, it's because there's insufficient data to create the agreements. Enough. Let's go have a beer and invent the experiment that will resolve this.

[Neil deGrasse Tyson]

There you have it. Yeah. No.

[Steven Pinker]

So that would be the kind of norm, it goes against human nature. I think the clock, the progress of science shows it's the best way to do things. And even, of course, scientists are not immune to pissing contests, dominance contests. And that's, you know, at least we acknowledge it's a bad thing. For that norm to spread in journalism, in politics, in the court system would be a good thing. It would be transformative. Yes. More truth, less vituperation.

[Neil deGrasse Tyson]

Once again, science saves the day. Science.

[Chuck Nice]

And he said vituperation. He doubled down on you. There it is. I see what he did there. Yeah. I think we gotta call it quits there. Oh, my God.

[Neil deGrasse Tyson]

That's a great conversation, man.

[Chuck Nice]

Let me see if I can take us out with a quick cosmic perspective. With your permission.

[Gary]

If you're feeling it, do it, my man.

[Steven Pinker]

Yeah, yeah.

[Chuck Nice]

I spent my life studying the universe, which is a huge complex place. All the laws of physics, I learn in physics class, are applied in some place, in some way at some time in the unfolding universe. Also the laws of chemistry and our search for life in the universe. There's the biology that we bring with us, all of this. And every time I reflect on that, I think to myself, this is not the hardest thing we can think about out there. You know what the hardest thing is? The human mind. What's going on inside there? And we've got psychologists with neuroscientists. There's a whole field trying to figure ourselves out. And I'm glad I do something as easy as astrophysics relative to what they've got to worry about. And I just hope that the study of the human mind by the human mind is not the most complex thing we ever have to tackle in this universe. But if it is, get ready for that ride. Because the human mind is not logical, it's not rational. Only occasionally it was not only the source of everything we value and call civilization, it may actually be the end of it as well if we're not careful. That's a cosmic perspective. Stephen, thanks for joining us.

[Steven Pinker]

Thank you so much. All right, it's been a great pleasure.

[Chuck Nice]

Steven Pinker's latest book. Give me the title again.

[Steven Pinker]

When everyone knows that everyone knows you got it.

[Neil deGrasse Tyson]

There you go. Chuck, always a pleasure.

[Chuck Nice]

All right, Gary.

[Gary]

Pleasure, my friend.

[Chuck Nice]

This has been StarTalk Special Edition. Neil DeGrasse Tyson, your personal astrophysicist. As always, keep hooking up.

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