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  • Published: 23 September 2025
  • ISBN: 9780241618837
  • Imprint: Allen Lane
  • Format: Trade Paperback
  • Pages: 384
  • RRP: $39.99

When Everyone Knows That Everyone Knows...

Common Knowledge and the Science of Harmony, Hypocrisy and Outrage





One of the world’s greatest thinkers investigates the logic and psychology of common knowledge

As a cognitive scientist, the ultimate subject of Steven Pinker’s fascination is how we think about each other’s thoughts, ad infinitum. It sounds impossible, but Steven Pinker shows that we do it all the time. This awareness, which we experience as something that is public or \"out there,\" is called common knowledge, and it has a momentous impact on our social, political, and economic lives.

Common knowledge, Pinker shows, can make sense of many of life’s enigmas: financial bubbles and crashes, revolutions that come out of nowhere, the posturing and pretence of diplomacy, the eruption of social media shaming mobs and academic cancel culture, the awkwardness of a first date. But people also go to great lengths to avoid common knowledge—to ensure that even if everyone knows something, they can’t know that everyone else knows they know it. And so we get rituals like benign hypocrisy, veiled bribes and threats, sexual innuendo, and pretending not to see the elephant in the room.

In exploring the paradoxes of human behaviour, When Everyone Knows that Everyone Knows… invites us to understand the ways we try to get into each other’s heads, and the harmonies, hypocrisies, and outrages that result.

  • Published: 23 September 2025
  • ISBN: 9780241618837
  • Imprint: Allen Lane
  • Format: Trade Paperback
  • Pages: 384
  • RRP: $39.99

About the author

Steven Pinker

Steven Pinker is an experimental cognitive scientist. Currently Johnstone Professor of Psychology at Harvard, he has also taught at Stanford and MIT. He has won many prizes for his research, teaching, and his eleven books, including The Language Instinct, How the Mind Works, The Blank Slate, The Better Angels of Our Nature, and Enlightenment Now. He is a member of the National Academy of Sciences, a two-time Pulitzer Prize finalist, a Humanist of the Year, a recipient of nine honorary doctorates, one of Foreign Policy's 'World's Top 100 Public Intellectuals' and Time's '100 Most Influential People in the World Today'.

http://stevenpinker.com

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Praise for When Everyone Knows That Everyone Knows...

When Everyone Knows That Everyone Knows…is one of the most insightful books I’ve read about what makes us human and how we understand each other. It changed how I think about the interactions I have, and I bet it will do the same for you

Bill Gates

Think you know what others think about what you are thinking? It turns out you’re probably wrong. And thanks to When Everyone Knows, now we know why. Once you read this book, you’ll never view human behavior quite the same way again

<b>Jonah Berger, <i>New York Times</i> bestselling author of <i>Contagious</i> and <i>The Catalyst</i> </b>

A masterful look behind the curtain at the calculations that propel us forward. With his brilliant knack for exposing what we take for granted, celebrated cognitive psychologist Steven Pinker explores, among many phenomena, our very human tendency to reveal information strategically, only letting others see what we want them to see

<b>Annie Duke, bestselling author of <i>Thinking in Bets</i> and <i>How to Decide</i> </b>

A lively exposition of one of the most important and basic concepts in game theory, and the surprising ways it plays out in human affairs

<b>Robert Aumann, Nobel Laureate in Economics and Professor Emeritus at the Hebrew University of Jerusalem </b>

Insight packed. With brisk authority, Pinker shows that a key aspect of being human, sociality, depends on a mutual understanding of intentions, which allows us to make sense of responses like laughing and blushing and phenomena as various as myth-making and online cancel culture

<b>Daron Acemoglu, Nobel Laureate in Economics and <i> New York Times </i> bestselling author of <i> Why Nations Fail </i></b>