In Talking to Strangers: What We Should Know About the People We Don’t Know (2019), journalist and author Malcolm Gladwell investigates why we face so many problems when interacting with strangers. He was inspired to search for the underlying causes of our miscommunications following the death of Sandra Bland, a black woman who was pulled over by a white police officer for a minor traffic infraction in 2015. Bland should have been let go with a warning; instead, a disastrous encounter escalated until Bland was arrested and put in jail, where she killed herself a few days later.

There were allegations of racism and misconduct following Bland’s suicide, but Gladwell believes that there is more to the story. There is something fundamentally flawed with how we make sense of strangers. To dig deeper into the matter, Gladwell examines numerous stories of interactions between strangers in which something went very wrong. He draws upon research from the social sciences to explain why each of these episodes happened the way they did.

Part 1 introduces two “puzzles” that will be addressed in the book: Why are we so bad at knowing when strangers are lying, and why are we sometimes even more prone to misunderstanding a stranger after having met them? Gladwell illustrates these problems with stories of the CIA being deceived by double agents and Neville Chamberlain being deceived by Adolf Hitler. Part 2 examines the psychologist Tim Levine’s truth-default theory, which holds that we tend to assume that people are telling the truth. It takes a substantial amount of evidence to the contrary for us to become convinced that someone is lying. Gladwell explores how our inclination to give people the benefit of the doubt allowed a spy, a con artist, and a rapist to get away with their crimes for years on end. Nevertheless, he concludes that society would be far worse if we did not default to truth.

The assumption that people are transparent is discussed in Part 3. Real life, Gladwell claims, is not like the TV show Friends. We do not wear our emotions on our sleeves. The problem is that we often assume that we can easily and reliably interpret a stranger’s facial expressions and behavior, as if they provided a window into the stranger’s inner state. That assumption has led many people astray, including the investigators who were convinced that Amanda Knox was guilty of murder, and numerous people who mistakenly thought their sexual partner had given consent.

If our strategies for making sense of strangers are unreliable, then what can we do? Part 4 discusses a suspected terrorist who confessed to a long list of crimes after being interrogated by the CIA for years. The problem is that no one is sure whether all of the things he confessed to actually happened. Despite our best efforts to see into other people’s minds, it simply isn’t possible. Gladwell claims that instead of focusing on how we can do a better job at figuring out strangers, we should humbly accept that we can’t know everything we want to know.

Part 5 examines how context—the time, place, and conditions someone is in—can shape a person’s behavior. Suicide rates thus are tied to the availability of suicide methods, and crime is tied to particular locations. When talking with strangers, we often fail to fully consider such contextual factors. In the final chapter of the book, Gladwell returns to the story of Sandra Bland, noting the mistakes that the police officer made in the encounter. He failed to default to truth, instead treating Bland with suspicion. He failed to realize that her agitated demeanor did not mean she was a criminal. He failed to consider anything about her world.

These are the same kinds of mistakes that we, as a society, make again and again when we talk with strangers. All too often, we confidently assume that we have judged people correctly based on the slightest of clues. Gladwell recommends that we accept that our tendency to default to truth is ultimately a good thing, and that we accept that there will always be things we don't know about other people. Talking to Strangers is a book about how we should have more humility and self-awareness when talking with people we don’t know.