Steven Pinker’s new book shows how he’s become a contradictory figure

When Everyone Knows That Everyone Knows
Steven Pinker (Allen Lane (UK); Scribner (US) Out 23 September)

Steven Pinker’s new book perfectly encapsulates what a contradictory figure he has become. Much of it is a clear, fascinating explanation of a major psychological phenomenon. But then he starts telling you what he thinks about current affairs.

Pinker is a psychologist at Harvard University who has written a string of popular science books. Some, like Words and Rules, are rooted in his own research and are a good read. Others venture further afield, such as The Better Angels of Our Nature, which argues there has been a long-term decline in violence in human societies.

The books in the latter category have become massive bestsellers, but they have also been kicked around by reviewers arguing that Pinker is way out of his depth. In The Better Angels of Our Nature, he had to confront the obvious exception to the trend of declining violence: the 20th century, which saw two world wars, the Holocaust and much more. To address this, he cherry-picked statistics to suggest previous centuries saw higher death rates, and also proposed that the 20th century was a historical fluke, claims that met with stiff criticism.

So I approached Pinker’s latest book with some wariness. Which side of him would be on display: the thoughtful psychologist, or the overconfident pundit? Both, it turns out. His topic is “common knowledge”: things that everyone knows and, crucially, we all know that everyone knows. He neatly illustrates its importance through Hans Christian Andersen’s The Emperor’s New Clothes, in which a child innocently – and correctly – points out that the emperor is naked. As Pinker writes, “he wasn’t telling anyone anything they didn’t already know”, but he added to their knowledge, ensuring “that they now knew that everyone else knew what they knew”. That was enough for the crowd to start laughing.

Common knowledge can be transformative. Pinker imagines an oppressed population and an authoritarian government. If enough people protest, the regime will fall, no matter how many guns it has. But it is difficult to begin: if no one joins your protest, you may be massacred. You know that the government is awful, but does everyone else? And do they know that everyone knows? Only with common knowledge can people confidently take to the streets.

The first seven chapters develop this idea in detail, using examples from game theory and psychology. Pinker is a graceful and clear writer, and he does a good job of guiding readers through various tangled logic puzzles, even using cartoons and a famous exchange from Friends (“They don’t know that we know they know we know!”).

Occasionally, he makes an asinine aside. He remarks, for instance, that a logic puzzle was first published “in the politically innocent early 1950s”, which is a bizarre way to describe the era of the second Red Scare. Still, these are minor annoyances.

But then, in chapter eight, which traces the psychological roots of “cancel culture”, everything goes to hell. His argument is that cancel culture is a form of censorship, motivated by “the urge to prevent ideas from becoming common knowledge”. It might be OK if people privately believe that one ethnic group is inferior to another, he suggests, but if this became common knowledge, it would lead to discrimination. Hence the urge to crack down on those who share such sentiments publicly.

There might be something to Pinker’s analysis of what drives people to cancel, but it is impossible to tell because his discussion of cancel culture is so poor. All his examples come from the liberal left, but the right also cancels: such was the fate of the Chicks (formerly the Dixie Chicks), who opposed the 2003 invasion of Iraq. And he never considers cases of people cancelled for genuine harms, which is analogous to writing about the criminal justice system by only telling stories about miscarriages of justice.

The final chapter covers how we decide whether to keep something semi-private or make it common knowledge. Pinker concludes that it depends on specifics. Thank heavens you’re here, Steven. When he sticks to psychological research, he is fascinating. It is a shame he wanders off course.

Michael Marshall is a writer based in Devon, UK

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