When Everyone Knows That Everyone Knows...: Common Knowledge and the Science of Harmony, Hypocrisy and Outrage

As a cognitive scientist, the ultimate subject of Steven Pinkers fascination is how we think about each others thoughts about each others 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 lifes 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 knowledgeto ensure that even if everyone knows something, they cant 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 others heads, and the harmonies, hypocrisies, and outrages that result.