“We have come to the end of a really good run,” Casner concludes. Casner thinks we should act like pilots in our own homes. He usually publishes in journals such as Aviation, Space, and Environmental Medicine (one of his recent papers investigated the worthy question of airline pilots’ “knowledge and beliefs about over-the-counter medications”). Parents watching kids at a swimming pool should utilize a “water-watcher” card to make attentional handoffs official: the person holding the card watches the kids, and must pass the card on to someone else before looking away from the pool and communing with his phone. Shortly after reading Casner’s discussion of the dangers of kayaking while intoxicated, I had a beer and went kayaking. Just as pilots must follow the rules at all times—no taxiing without approval from air-traffic control—so pedestrians should wait patiently at the crosswalk for a “Walk” sign: only ten per cent of people wait, and thirty-eight per cent of all pedestrian collisions happen in crosswalks. Casner finds the word “accident” misleading; he distinguishes between “mistakes” and “errors.” A mistake is “the flawless execution of a mostly dumb idea”—it’s what happens when you should have known better. What if it’s one in five? They argue that a certain amount of danger is not just acceptable but desirable—that people in past eras were tougher, more independent, more courageous. population is around his daughter’s age, then “one out of every five hundred kids in the country gets wheeled into the E.R. In psychological terms, we perceive “affordances for action” (the blade of the screwdriver prying off the lid), but not “affordances for harm” (the blade breaking off, flying upward, and stabbing us in the eye). Reading “Careful: A User’s Guide to Our Injury-Prone Minds” by Steve Casner may make you want to stay in—a mistake, he writes, since fifty per cent of all fatal accidents happen at home.CreditJAY P. Many of the hundred and forty thousand people who fall off ladders every year do so because they stand on the rung that says “Not a step.” That’s a mistake. Then again, she hasn’t read “Careful: A User’s Guide to Our Injury-Prone Minds,” a terrifying primer on the absurd and humiliating dangers of daily life by the psychologist and safety expert Steve Casner. Twenty-one thousand people hurt themselves with food processors; twenty-eight thousand injure themselves with hammers; forty thousand are wounded, somehow, by their washing machines. Finally, there is “the social appeal of the daredevil.” Casner recalls one night when he left a San Francisco bar on his skateboard and slalomed across both sides of the street: “A car passed me and someone yelled out the window, ‘You go, skater!’ ” He now regrets “helping to promote a social norm of being reckless.” Still, people don’t need bad examples to do crazy things; they do them on their own, because there is something anarchic in human nature. “We have wrung all the big gains we’re going to get from putting rubber corners on stuff and saying, ‘Hey, don’t do that.’ ” From here on out, if we want to be safer, we will have to do it ourselves, by making better decisions. Casner has some theories about why this is happening. But then the decline in the accidental-death rate stopped—and, since 2000, it has actually risen. It’s hard to balance fun and risk, he admits, because they “are so often one and the same thing.” Even so, Casner argues, we’re in the midst of a safety crisis. During drunken high-school parties, Ryan and his brother Jesse led their friends in leaping from the roof to the trampoline to the water. He had bunk beds. Every year, Casner writes, people “trip while walking down the sidewalk too close to the curb, fall into the street, and get hit by cars, trucks, and buses.” Reading “Careful” makes you want to stay in—a mistake, Casner writes, since fifty per cent of all fatal accidents happen in “that house of horrors we call home.” Puttering around the house is so dangerous that even people with hazardous jobs, such as electric-power-line installers, are more likely to do themselves in at home than at work. It feels good to thumb your nose at authority—even at that of your own better judgment. They testify to our duality; they happen when we assert and defy ourselves simultaneously. He interviews Ryan, an acquaintance who, as a young man, positioned the family trampoline between the roof of their house and its swimming pool. each year solely because of bunk beds.” He continues, “How many kids even have bunk beds? “There is never perfect compliance with these procedures, but it brings the chaos down to a more manageable level.” To an extent, we are accident-prone because we are imaginative. She’s probably contemplating something abstract—the passage of time, the obscurity of fate. A French psychologist surveyed E.R. One is “risk homeostasis”—our tendency, once we’re safer, to take more risks. In 2010, fifty-one thousand car crashes and four hundred and forty deaths resulted from objects, such as mattresses, falling off automobile roof racks and into traffic. The core problem is that minds wander. As a kid, he rode unsecured in the back of his grandfather’s pickup truck, leaning over the side to get closer to the road. The pilots rely on checklists to make sure no steps are skipped; they use “callouts”—“Gear down, flaps fifteen”—to insure that everyone is paying attention. Reading “Careful,” I felt the pull of anarchy myself. We are determined to use familiar tools in novel ways—we might use a knife handle, say, to break up ice in the freezer, or a screwdriver to pry open a stuck drawer. MORGAN / GETTY
When Clarissa Dalloway thinks that it’s “very, very dangerous to live even one day,” what, exactly, does she have in mind? Some people think that we live in a safety-obsessed age. “Why not make everybody call out ‘Hands clear’ when closing a door?” he asks. Casner worries that our optimism about our own plans might be an insurmountable part of our evolutionary heritage. Recalling the time he fell off a chair while trying to replace the batteries in his smoke detector—he should have used a ladder—Casner reflects that, in our primate past, it was the climbers who ate. We’ll have to become the kinds of people who, before trampoline-bouncing into the pool, think twice (or, more likely, for the first time). Every commercial flight has two pilots, two air-traffic controllers, and even two flight computers. (Bicyclists who wear helmets, for example, tend to ride closer to cars than those who don’t.) New inventions play a role—smartphones that distract us, medications that confuse us; so does the new popularity of adventure sports, such as rock climbing. In 1918, one in twenty people died in an accident of some kind; by 1992, that number had been reduced to one in forty, through regulations, innovations, and public-awareness campaigns. Pilots never multitask: if a pilot finds that she has to look at a map, she tells her co-pilot, “It’s your airplane,” and waits for an affirmative response—“I’ve got the jet”—before shifting focus. “The U.S. When the dry cleaning came home, he ran around with the plastic bag over his head; he made gunpowder with his chemistry set; he biked around town, helmetless, with a friend’s iguana on his shoulders. Accidents come in many forms. Many injuries happen when people are trying to “cook, make, decorate, or fix something.” Another significant factor is that people are living longer, into frail, accident-prone old age. There’s the ascendant culture of D.I.Y.: “People are once again building their own furniture, blowing glass, upgrading their homes, and chopping and chainsawing their own firewood,” Casner writes. In “Careful,” Casner treats quotidian life like a NASA space mission. The problem is that we imagine how things will go right but not how they will go wrong. When his young daughter requests a bunk bed for her room, a “quick fact check” tells him that “about thirty-six thousand kids per year are taken to an emergency room following a bunk bed injury.” Casner calculates that, if six per cent of the U.S. In 2015, after almost a century of steady decline in car fatalities, driver, pedestrian, and cyclist deaths shot up eight, ten, and twelve per cent, respectively. A hundred and twenty-five thousand people die annually because of “medication nonadherence,” and, according to the American Cancer Society, untold numbers perish because they think their cancer symptoms will “resolve themselves with time” and so never visit a doctor—an accidental death in slow motion. But errors are inevitable: even a competent and well-trained pilot will, eventually, glance at a lever in the “On” position and think that it is actually “Off.” The psychologist James Reason has found that people are aware of their own errors only eighty-five per cent of the time. That would mean one percent of all kids with bunk beds are heading to the E.R.” Bunk-bed request: denied. She isn’t worried about stumbling over her own feet and careening into London traffic. Casner is no ordinary worrywart. Other kinds of accidents are more common, too, and we are now, Casner says, about as safe as we were thirty years ago. “Today, Ryan is an investment advisor with three kids,” Casner writes, and Casner himself enjoys skateboarding around San Francisco. In the end, “Careful” illuminates the mental strangeness of accidents. patients who had been in car accidents; he found that half of them were lost in thought at the moment of the crash. Needless to say, Casner’s chapter on accidents involving infants and small children is more horrifying than all these statistics combined. Casner writes that around sixty thousand kids get their fingers caught in doors each year, often on the “hinge side”; around a thousand suffer amputation. Even workers in nuclear power plants make “errors in reading gauges, interpreting indicator lights, and selecting the wrong button to push,” Casner writes. He is a jet and helicopter pilot with degrees in computer science and “intelligent systems”; he works as a research psychologist at NASA, where he studies safety as part of the “human factors” division. Casner devotes several pages to the proper technique for slicing a bagel; annually, three hundred and thirty-three thousand Americans cut themselves so badly with kitchen knives that they have to go to the E.R. Casner recalls his own childhood, in the unsafe nineteen-sixties. airline crash rate over the past ten years is approaching percent,” Casner writes, in large part because pilots, in addition to training themselves not to make mistakes, also employ various systems designed to combat error.