I was a third-grader when a newspaper heiress named Patricia Hearst was snatched outside her apartment in Berkeley, Calif. The assailants were part of a fringe revolutionary group few had ever heard of called the Symbionese Liberation Army.

In the winter of 1974 and for months afterward, anyone living in the San Francisco Bay area was awash in the story — its every twist and turn was front-page, above-the-fold news in the San Francisco Examiner that landed on our doorstep; Hearst’s father was the paper’s editor and president. His single-minded focus on the safe return of his daughter became our single-minded focus, too. At least for a time.

Even now, I can recall the smallest details of the story as if they were part of a Patricia Hearst “Jeopardy” category: the name of Hearst’s boyfriend at the time (Who is Steven Weed?), the address of the Berkeley apartment from which she was taken (What is 2603 Benvenue St.?), the nom de guerre she adopted when she announced that she had decided to join the SLA (Who is Tania?) and the name of the bank she helped the group rob (What is Hibernia?).

When Hearst was finally arrested after some 19 months with the SLA, her lawyers said she couldn’t be held responsible for her actions: She was acting out of self-preservation, they argued. To stay alive, Hearst had to do things she might not have otherwise done. She was coerced, they claimed — not converted.

The jurors at her trial were unconvinced. They found her guilty of bank robbery and use of a firearm during the commission of a felony; a judge sentenced her to seven years in prison.

“The world wasn’t ready to consider the implications of dark persuasion when it came to her case,” Joel E. Dimsdale writes in his faintly gloomy but riveting new book, “Dark Persuasion: A History of Brainwashing From Pavlov to Social Media.” “She was tarred with accusations of being an entitled heiress, a child of privilege, the product of too much leniency.”

In other words, her brainwashing defense didn’t fly.

The term “brainwashing” dates to 1950, when a journalist and former OSS member named Edward Hunter wrote an article explaining why, in the waning days of the Korean War, American POWs defected to Korea and China. According to Hunter, the prisoners were embracing neither the enemy nor its ideals. Instead, they had been subjected to what the Chinese called “xi nao,” or “wash brain,” and had, as a result, lost any sense of reason. And this was only the beginning, Hunter warned.

“ ‘Brain-washing’ . . . is the terrifying new Communist strategy to conquer the free world by destroying its mind,” he wrote in his subsequent book, “Brain-Washing in Red China.” “The Communists in China are utilizing this combination of misapplied psychology and perverted evangelism” to attack the free world. The implication was that America needed to respond in kind.

Dimsdale makes clear that Hunter’s observations — coming in the midst of the Red Scare — set off a flurry of activity: intense and often unethical research into how the human mind behaves under stress and how it might be manipulated once it neared its breaking point.

Among other things, the United States began studying Chinese and Korean interrogation techniques to create an effective American weapon in this new psychological war. The U.S. government began partnering with scientists and universities, Dimsdale reveals, looking for ways to confront the communist menace and “mount a brain war offense.”

The CIA, for its part, offered grants to dozens of universities in the 1950s and 1960s for research focused on such things as “the evaluation and development of any method by which we can get information from a person against his will and without his knowledge.”

The CIA bankrolled studies on interrogation techniques and truth serums; it launched classified programs with code names like Bluebird, Artichoke and MKUltra. It conducted tests with LSD, studied emotional stress, developed “knockout drops” to render victims unconscious, and researched how amnesia could be induced by concussions and how social isolation could affect behavior — all in a bid to understand this idea of brainwashing.

Dimsdale takes readers through it all, animating the journey with a clear, energetic writing style that shows how the art of dark persuasion a generation ago led almost inevitably to today’s misinformation, cyberbullying and cultlike behavior on the Internet. The only disappointment is that Dimsdale takes us to the brink of this argument without fully developing it. He devotes only about a half a dozen pages to social media and the way it has come to coerce us all. I would have liked a chapter or two.

Perhaps I’m so hungry for his analysis on this because I’ve spoken to so many people who stormed the Capitol on Jan. 6 — and to a man and woman, they were all convinced that they were righting a wrong. President Donald Trump used social media and rallies full of misinformation to convince a huge portion of the country that an election had been stolen and it needed to be rolled back. If that isn’t a form of brainwashing, I’m not sure what is.

“Social media has gone from techno-utopianism to dystopic weaponization,” Dimsdale writes in the conclusion of his book. “Perhaps Timothy Leary was more accurate than he realized when he branded the internet the new LSD. Tomorrow’s brainwashers could not help exploring the possibilities.”

Which makes me wonder how things might have unfolded differently if that jury in the 1970s weighing the evidence in the Hearst trial had had the benefit of Dimsdale’s “Dark Persuasion” as they deliberated. Would the defense team’s brainwashing argument have found more traction? Or would we need something like the subsequent mass murder at Jonestown — which happened just two years after the Hearst trial — to show that sensible people can be driven to do things they might not otherwise do?

Dark Persuasion

A History of Brainwashing From Pavlov to Social Media

By Joel E. Dimsdale

Yale.
284 pp. $28