When Everyone Knows That Everyone Knows

The book explores the concept of “common knowledge”—the shared, public awareness of thoughts and beliefs among people—and its profound impact on social, political, and economic life. Pinker, known for works like Enlightenment Now, argues that this complex awareness, which he refers to as thinking about “each other’s thoughts, ad infinitum,” explains many of life’s enigmas, such as financial bubbles and crashes, sudden revolutions, social media shaming, and awkward first dates. Conversely, the book also examines how people often go to great lengths to avoid common knowledge, leading to social rituals like hypocrisy, veiled threats, sexual innuendo, and ignoring “the elephant in the room.” By exploring these paradoxes, Pinker invites the reader to understand the ways humans try to read each other’s minds and the resulting “harmonies, hypocrisies, and outrages.”