By eerie coincidence, I began reading William J. Bernstein’s “The Delusions of Crowds: Why People Go Mad in Groups” in early January and was deep into it on Jan. 6. I kept reading in the days that followed the unprecedented insurrection at the Capitol, putting the book aside occasionally to look at the scores of videos taken by participants before and during the rioting. ProPublica, the investigative news site, acquired more than 500 of these videos and assembled them into a compelling new kind of documentary.

The people in these clips fit with what Bernstein describes as victims of delusions. In this instance they were victims of our deluder in chief, who concocted false tales of election fraud that he repeated again and again to convince his followers that Joe Biden had stolen the 2020 election. At a rally on Jan. 6, President Donald Trump urged the crowd to march on the Capitol, “show strength” and “stop the steal.” At his bidding, the believers set off for the Capitol. The rioters’ explanations of their actions in the ProPublica videos put on full display Bernstein’s conclusions about the delusions of crowds. Bernstein wants us to understand that human beings are not remotely as smart or as rational as we would like them to be. Only rarely are people truly analytical about anything. We make things up constantly, then claim that our inventions are true.

“Novelists and historians have known for centuries that people do not deploy the powerful human intellect to dispassionately analyze the world, but rather to rationalize how the facts conform to their emotionally derived preconceptions,” Bernstein writes. “Over the past several decades, psychologists have accumulated experimental data that dissect the human preference of rationalization over rationality. When presented with facts and data that contradict our deeply held beliefs, we generally do not reconsider and alter those beliefs appropriately. [Instead] . . . we avoid contrary facts and data, and when we cannot avoid them, our erroneous assessments will occasionally even harden and, yet more amazingly, make us more likely to proselytize them. In short, human ‘rationality’ constitutes a fragile lid perilously balanced on the bubbling cauldron of artifice and self-delusion.”

Storytelling trumps analyzing nearly always, Bernstein writes. Narratives, not analytical constructs or algebraic solutions, are what engage the human mind. But “the more we depend on narratives, and the less on hard data, the more we are distracted away from the real world,” he adds. This is how demagogic politicians and charismatic preachers can win us over, often despite their reliance on implausible narratives that beguile us. Reading Bernstein, I thought of Trump’s tales of Mexican rapists sneaking across our southern border, and Ronald Reagan’s “welfare queen.”

Bernstein is a neurologist with an MD and a PhD in chemistry who became an investment adviser and author. At the beginning of this, his eighth book, he warns that he won’t be writing about political delusions, but he adds coyly that “the reader will, however, encounter no great difficulty connecting the episodes described in the coming pages, as well as their underlying psychology, to manias of all types, particularly to the totalitarianism of the last century and the viral conspiracy theories of this one.” He is right about that.

His subjects are religious and financial manias. He succumbs to his own argument that narratives are more persuasive than analyses or calculations, and he loves telling stories, which he does well. That makes this a fun book to read, though a windy one, as the long quotation in the previous paragraph suggests. Bernstein is a good writer, but his internal editor occasionally takes an unearned vacation.

His inspiration and guide for this book was a 19th-century bestseller, “Extraordinary Popular Delusions and the Madness of Crowds” by a Scottish writer named Charles Mackay, who was just 27 when he wrote it. Mackay’s book is still in print 180 years later and still popular among students of stock market behavior. Bernstein’s version unabashedly echoes Mackay’s, enriching its analysis with the findings of modern social scientists who study the irrational human behavior that intrigues both authors.

Both Bernstein and Mackay put religious manias and economic bubbles in the same category of mass delusions. The most powerful narratives, Bernstein argues, involve “end-times” stories like the one in the last chapter of the New Testament, the Book of Revelation, which foretells that Jesus will return to rule the world for 1,000 years — its final 1,000 years. “The most prominent, and dangerous, mass delusion running like a red thread through human history, [is] the end-times narrative,” he writes. He devotes a large portion of his book to examples of delusional crowds embracing end-times stories, from the Middle Ages to our day, in the United States, Israel and the Arab world.

Bernstein writes that secular Americans don’t appreciate the extent of fundamentalist Christian belief in the end-of-the-world scenario in the Book of Revelation or the associated notion that the reestablishment of a Jewish state in Palestine in 1948 foretold the fulfillment of the biblical prophesy of Armageddon. Many evangelical Christians believe that this will be a devastating military confrontation heralding the return of Jesus. Bernstein fears that an evangelical Christian believer in a key position — an Air Force officer commanding American intercontinental ballistic missiles, for example — could someday initiate a nuclear holocaust to try to bring on Armageddon, like a real-life Dr. Strangelove.

Mackay is famous for arguing that “men . . . think in herds [and] . . . they go mad in herds, while they only recover their senses more slowly, and one by one.” Bernstein agrees, and he enjoys sending up the fakers who exploit the herd phenomenon, be they promoters of stock scams or self-serving proselytizers of religion. The shots he takes find their marks — the Rev. Pat Robertson, for example, the evangelist and onetime presidential candidate who has often claimed to be in direct communication with God. “Robertson . . . has misheard God with some frequency,” Bernstein writes, “as when He told him that the world would end in 1982, that a tsunami would hit the Pacific Northwest in 2006, that worldwide mass terrorist killings would occur in 2007, and that Mitt Romney would win the 2012 presidential election.”

Americans believe in myths and concoct narratives in huge numbers, Bernstein writes, a fact that sets us apart from all the other industrialized nations, none of which is remotely as religious as we are. Bernstein recounts the astounding commercial success of what he calls “rapture fiction,” evangelical science fiction spun around the Book of Revelation’s prediction that on the eve of the end of the world, believing Christians will be whisked from Earth to heaven — “raptured” — while hundreds of millions of nonbelievers and non-Christians will be slaughtered. A series of novels based on this possibility by Tim LaHaye and Jerry Jenkins, the “Left Behind” novels, have sold more than 65 million copies. Equally impressive sales have been recorded by “The Late Great Planet Earth” by Hal Lindsey and Carole C. Carlson, purportedly a nonfiction work describing the biblical prophesies that put the future of the world and all of humanity in doubt.

Lindsey had many acolytes, Bernstein notes, including Reagan and several members of his Cabinet. Perhaps more important, LeHaye, Lindsay and like-minded preachers with large followings have had a palpable impact on public opinion. In a 2010 Pew Research Center poll cited by Bernstein, a third of Americans said they expected Jesus to return to Earth in their lifetime.

But we don’t need a poll to confirm Mackay’s and Bernstein’s conclusion that people tend to believe what they want to believe, whether or not hard facts and cold reason support their views. We know, for example, that on Nov. 3, more than 74 million Americans voted to reelect a man whom a slew of serious historians have already identified as the worst president in American history, a man whose personal behavior was never remotely dignified, who often behaved like a compulsive liar with an uncontrollable need for approval and applause. His indifference to Americans who did not share his own attributes — European ancestry, white skin, economic comfort — was obvious. That indifference often became outright hostility that reeked of ethnic prejudice. He faced one huge crisis as president and utterly botched it. And yet, those 74 million-plus citizens evidently wanted four more years of making America great again. How could that happen?

Explains Bernstein: “When compelling narrative [Make America Great Again, for example] and objective fact collide, the former often survives, an outcome that has cursed mankind since time immemorial.”

The Delusions of Crowds

Why People Go Mad in Groups

By William J. Bernstein

Atlantic Monthly Press.
482 pp. $35