Prologue

After a bumpy flight, fifteen men dropped from the Montana sky. They weren’t skydivers. They were smokejumpers: elite wildland firefighters parachuting in to extinguish a forest fire started by lightning the day before. In a matter of minutes, they would be racing for their lives.

The smokejumpers landed near the top of Mann Gulch late on a scorching August afternoon in 1949. With the fire visible across the gulch, they made their way down the slope toward the Missouri River. Their plan was to dig a line in the soil around the fire to contain it and direct it toward an area where there wasn’t much to burn.

After hiking about a quarter mile, the foreman, Wagner Dodge, saw that the fire had leapt across the gulch and was heading straight at them. The flames stretched as high as 30 feet in the air. Soon the fire would be blazing fast enough to cross the length of two football fields in less than a minute.

By 5:45 p.m. it was clear that even containing the fire was off the table. Realizing it was time to shift gears from fight to flight, Dodge immediately turned the crew around to run back up the slope. The smokejumpers had to bolt up an extremely steep incline, through knee-high grass on rocky terrain. Over the next eight minutes they traveled nearly 500 yards, leaving the top of the ridge less than 200 yards away.

With safety in sight but the fire swiftly advancing, Dodge did something that baffled his crew. Instead of trying to outrun the fire, he stopped and bent over. He took out a matchbook, started lighting matches, and threw them into the grass. “We thought he must have gone nuts,” one later recalled. “With the fire almost on our back, what the hell is the boss doing lighting another fire in front of us?” He thought to himself: That bastard Dodge is trying to burn me to death. It’s no surprise that the crew didn’t follow Dodge when he waved his arms toward his fire and yelled, “Up! Up this way!”

What the smokejumpers didn’t realize was that Dodge had devised a survival strategy: he was building an escape fire. By burning the grass ahead of him, he cleared the area of fuel for the wildfire to feed on. He then poured water from his canteen onto his handkerchief, covered his mouth with it, and lay facedown in the charred area for the next fifteen minutes. As the wildfire raged directly above him, he survived in the oxygen close to the ground.

Tragically, twelve of the smokejumpers perished. A pocket watch belonging to one of the victims was later found with the hands melted at 5:56 p.m.

Why did only three of the smokejumpers survive? Physical fitness might have been a factor; the other two survivors managed to outrun the fire and reach the crest of the ridge. But Dodge prevailed because of his mental fitness.

* * *

When people reflect on what it takes to be mentally fit, the first idea that comes to mind is usually intelligence. The smarter you are, the more complex the problems you can solve—and the faster you can solve them. Intelligence is traditionally viewed as the ability to think and learn. Yet in a turbulent world, there’s another set of cognitive skills that might matter more: the ability to rethink and unlearn.

Imagine that you’ve just finished taking a multiple-choice test, and you start to second-guess one of your answers. You have some extra time—should you stick with your first instinct or change it?

About three quarters of students are convinced that revising their answer will hurt their score. Kaplan, the big test-prep company, once warned students to “exercise great caution if you decide to change an answer. Experience indicates that many students who change answers change to the wrong answer.”

With all due respect to the lessons of experience, I prefer the rigor of evidence. When a trio of psychologists conducted a comprehensive review of thirty-three studies, they found that in every one, the majority of answer revisions were from wrong to right. This phenomenon is known as the first-instinct fallacy.

In one demonstration, psychologists counted eraser marks on the exams of more than 1,500 students in Illinois. Only a quarter of the changes were from right to wrong, while half were from wrong to right. I’ve seen it in my own classroom year after year: my students’ final exams have surprisingly few eraser marks, but those who do rethink their first answers rather than staying anchored to them end up improving their scores.

Of course, it’s possible that second answers aren’t inherently better; they’re only better because students are generally so reluctant to switch that they only make changes when they’re fairly confident. But recent studies point to a different explanation: it’s not so much changing your answer that improves your score as considering whether you should change it.

We don’t just hesitate to rethink our answers. We hesitate at the very idea of rethinking. Take an experiment where hundreds of college students were randomly assigned to learn about the first-instinct fallacy. The speaker taught them about the value of changing their minds and gave them advice about when it made sense to do so. On their next two tests, they still weren’t any more likely to revise their answers.

Part of the problem is cognitive laziness. Some psychologists point out that we’re mental misers: we often prefer the ease of hanging on to old views over the difficulty of grappling with new ones. Yet there are also deeper forces behind our resistance to rethinking. Questioning ourselves makes the world more unpredictable. It requires us to admit that the facts may have changed, that what was once right may now be wrong. Reconsidering something we believe deeply can threaten our identities, making it feel as if we’re losing a part of ourselves.

Rethinking isn’t a struggle in every part of our lives. When it comes to our possessions, we update with fervor. We refresh our wardrobes when they go out of style and renovate our kitchens when they’re no longer in vogue. When it comes to our knowledge and opinions, though, we tend to stick to our guns. Psychologists call this seizing and freezing. We favor the comfort of conviction over the discomfort of doubt, and we let our beliefs get brittle long before our bones. We laugh at people who still use Windows 95, yet we still cling to opinions that we formed in 1995. We listen to views that make us feel good, instead of ideas that make us think hard.

At some point, you’ve probably heard that if you drop a frog in a pot of scalding hot water, it will immediately leap out. But if you drop the frog in lukewarm water and gradually raise the temperature, the frog will die. It lacks the ability to rethink the situation, and doesn’t realize the threat until it’s too late.

I did some research on this popular story recently and discovered a wrinkle: it isn’t true.

Tossed into the scalding pot, the frog will get burned badly and may or may not escape. The frog is actually better off in the slow-boiling pot: it will leap out as soon as the water starts to get uncomfortably warm.

It’s not the frogs who fail to reevaluate. It’s us. Once we hear the story and accept it as true, we rarely bother to question it.

* * *

As the Mann Gulch wildfire raced toward them, the smokejumpers had a decision to make. In an ideal world, they would have had enough time to pause, analyze the situation, and evaluate their options. With the fire raging less than 100 yards behind, there was no chance to stop and think. “On a big fire there is no time and no tree under whose shade the boss and the crew can sit and have a Platonic dialogue about a blowup,” scholar and former firefighter Norman Maclean wrote in Young Men and Fire, his award-winning chronicle of the disaster. “If Socrates had been foreman on the Mann Gulch fire, he and his crew would have been cremated while they were sitting there considering it.”

Dodge didn’t survive as a result of thinking slower. He made it out alive thanks to his ability to rethink the situation faster. Twelve smokejumpers paid the ultimate price because Dodge’s behavior didn’t make sense to them. They couldn’t rethink their assumptions in time.