Steven Pinker on the Recursive Loop That Made Us Human

Source: Simon & Schuster

In Hans Christian Andersen's folktale, The Emperor's New Clothes, when a child cries out that the emperor is naked, he isn't revealing a secret. Everyone already knows it. What changes in that instant is that everyone now knows that everyone else knows. That shift—from mutual knowledge to common knowledge, from private recognition to public awareness—topples the illusion. It's also the central insight of cognitive scientist Steven Pinker's new book, When Everyone Knows That Everyone Knows . . .: Common Knowledge and the Mysteries of Money, Power, and Everyday Life.¹

Pinker argues that this layered awareness—knowing that others know that you know—binds societies together and, at times, tears them apart. From cooperation and civility to hypocrisy and moral outrage, our social lives depend on nested models of what others think. His book reveals the hidden logic behind these loops of awareness—how they govern polite conversation, collective action, and even the stability of nations.

Common Knowledge

We navigate common knowledge constantly—exchanging knowing glances, blushing² when norms are breached, laughing at shared jokes. Each depends on recursive mentalizing: our ability to represent what others think, and what they think we think.

With ordinary mutual knowledge, each person knows a fact. With common knowledge, everyone knows it, and everyone knows that everyone else knows it—and everyone knows that everyone else knows that, in an infinite regress. Human brains can't compute endless loops, so we rely on public cues and shared signals—eye contact, rituals, news headlines—to establish common knowledge without consciously working through each recursive level. A public protest or viral post changes behavior not by adding information but by making that information publicly self-evident.

For Pinker, this shift from private knowledge to common knowledge is the foundation of social coordination. It explains why markets stabilize or collapse, why reputations matter, and why hypocritically pretending not to know what everyone knows can sometimes keep the peace. Common knowledge allows individuals to act in concert but can also ignite moral panics and collective outrage.

Recursive Mentalizing Explains More Than You Think—Mediated by the Power of Language

Recursive mentalizing is a theme that has intrigued Pinker for decades. In his previous books, he has examined how it underlies language, cooperation, moral progress, and much else—for example, in The Stuff of Thought, The Better Angels of Our Nature, and Rationality.³

He reflects on this at the conclusion of When Everyone Knows That Everyone Knows:

"The power of cognition to take its own outputs and feed them back into more cognition is a theme that has run through all my books, and it fills me with awe even after decades of pondering human intelligence. It underlies the vast expressive power of language… It explains how human intelligence, having evolved to reason about survival and reproduction, can be extended to reason about science, philosophy and mathematics. It explains how human progress is possible… it implies that rationality itself is limitless… It's what's most special about our kind: we not only have thoughts, but have thoughts about our thoughts, and thoughts about our thoughts about our thoughts."⁴

In his 2008 paper on indirect speech, co-authored with Martin Nowak and James Lee, Pinker showed how people use veiled language—like saying "Gee, officer, is there some way we could take care of the ticket here?" instead of a direct offer of a bribe—to manage what becomes common knowledge. Such subtlety isn't about hiding meaning; it's about avoiding common knowledge—preventing the proposition from becoming mutually and publicly acknowledged in a way that would force a response. The point isn't plausible deniability of the message but deniability of common knowledge.⁵

In Better Angels, Pinker traced moral progress to expanding circles of empathy and to the growing capacity for self-reflection and reason—forms of recursive mentalizing that let us imagine others’ experiences, anticipate how we appear to them, and internalize shared norms. When Everyone Knows That Everyone Knows demonstrates how minds modeling other minds build the shared expectations that enable social coordination and civilization itself.

Pinker, whose academic research focuses on psycholinguistics, argues that human language is a biological adaptation—evolved for the complex communication that turns private thoughts into shared understanding and allows people to coordinate their actions. Conventions such as money or law depend entirely on this process: they exist only because everyone knows that everyone else accepts them. Civilization itself, in this sense, is made possible by common knowledge—and common knowledge, in turn, by our capacity for recursive mentalizing.

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The Moral Psychology of Knowing That We Know

Pinker reframes certain forms of hypocrisy—pretending not to know what everyone privately knows—not as deceit but as social lubricant: a way of avoiding making uncomfortable facts common knowledge. Societies can function only if some violations remain quietly known but not publicly affirmed. A drink in a paper bag or a polite fiction can preserve harmony by preventing mutual awareness from escalating into open confrontation. He argues that civility is what allows imperfect beings to cooperate.

By contrast, publicity—the sudden conversion of private knowledge into common knowledge—can unleash powerful moral forces. Social media amplifies this transformation, turning private awareness into public outrage when everyone sees that everyone else has seen the transgression.

Common knowledge can uphold norms, but it can just as easily magnify intolerance. Civilization depends on this delicate balance—knowing when to make knowledge common and when to let it remain tacit.

From Recursive Minds to Reflective Minds

While Pinker's focus in this book remains on social coordination rather than consciousness, his framework on recursive mentalizing invites intriguing questions about self-awareness (a subject he has also explored in his previous work).

The capacity to model other minds—to imagine what they think of us—typically entails constructing a representation of our own mind as it appears to them. This "social mirror" may have scaffolded the evolutionary emergence of genuine self-reflection. Developmental evidence suggests children develop a theory of mind about others between the ages of 3 and 5, before comparable metacognitive abilities about their own thoughts. Brain imaging studies show overlapping neural circuitry for social cognition and self-reflection.

This raises the possibility that self-awareness—one of the hallmarks of human consciousness—emerged not primarily from introspection but from first learning to model other minds. The same recursive machinery that enables social coordination might, when turned inward, create the reflective sense of self.⁶

The Collective Mind

In a parallel to individual self-awareness, common knowledge gives societies a kind of collective consciousness—the ability to see what everyone sees and act on shared understanding.

Public rituals and institutions create common knowledge by making shared beliefs visible and mutually acknowledged. When norms like human rights become common knowledge, they acquire moral force to reshape behavior globally. As Pinker argued in Better Angels, moral progress depends not merely on changing opinions but on those opinions becoming publicly recognized and mutually understood.

Civilization and Consciousness

When Everyone Knows That Everyone Knows reveals how shared awareness—the glue of cooperation, coordination, and culture—depends on recursive loops that make us human. These loops—between self and other, between private thought and public acknowledgment—form the hidden architecture of civilization and perhaps consciousness alike. We are creatures who think not only about the world but also about what others think about what we think.

That infinite regress may sound dizzying, but it's what makes empathy, morality, humor, and civilization possible. Whether the same recursive capacity that coordinates societies also gave rise to self-aware consciousness remains an open question—one that Pinker's framework on recursive mentalizing makes newly compelling. The leap that allowed a crowd to see the emperor's nakedness might, when turned inward, be what allows a mind to see itself.^7,8