The Brain, Explained


"Don't think, feel!" Bruce Lee's character exhorts his young son in Enter the Dragon (1973) as he teaches him to trust his instincts while learning to fight. By contrast, Ayn Rand favored "Don't feel, think!" when she wrote, "People don't want to think. And the deeper they get into trouble, the less they want to think." Like Plato, Rand proudly privileged reason over emotion. But which is the better approach for making decisions, Lee's feeling intuitively or Rand's thinking rationally?

According to Jonah Lehrer in How We Decide, they're both right. We humans would make better decisions if we understood how the brain reacts to various stimuli. The frontal cortex accesses different tools within its complex regions and uses that knowledge to choose when we should react intuitively and when we should figure things out rationally. Using fascinating real-life stories, studies conducted by respected psychologists and neuroscientists, and an entertainingly accessible style, Lehrer explains how the uniquely human frontal cortex sorts it all out and helps us decide.

For instance, Lehrer considers how quarterback Tom Brady surveys the position and forward direction of 21 moving players on a 5,000-square-yard playing field, anticipates where everyone will be next, and decides where and how fast to throw a football, all in less than two seconds, while other players are bearing down on him. Brainwave studies have shown that there isn't time for him to process the information and make a rational decision. The neural synapses aren't that fast. A quarterback's decision is made intuitively, through the part of the brain controlled by emotion. As Lehrer quotes Brady, "You just feel like you're going to the right place."

Lehrer also demonstrates what causes athletes, performers, public speakers, and everyday humans like you and me to "choke" on tasks for which we are perfectly prepared and skilled. He tells the stories of opera singer Renee Fleming, golfer Jean Van de Velde, and others to demonstrate the point. The problem comes from overthinking a task that the body has learned to perform instinctively. In short, the brain gets in its own way, as the reasoning synapses block the path of the emotional synapses. "A brain that can't feel can't make up its mind," Leher concludes (15).

Of course, mere feeling isn't sufficient for making the right decisions. A potential juror who says, "I can tell if someone's guilty just by looking at him" is more dangerous than a crook with a gun. Lehrer provides equally fascinating examples to demonstrate when the rational part of the brain needs to be in control. For example, he tells the compelling story of firefighters who tried to control a raging forest fire in the Rockies in 1949. When the blaze jumped a gulch and began racing toward them, most of them tapped into their brain's emotional side and tried to outrun the fire.

The captain, however, evaluated the situation rationally. He quickly took into account the dryness of the grass, the speed of the wind driving the fire, the slope of the hill they would have to run, and their unfamiliarity with the terrain on the other side of the crest. While his emotions screamed "Run!" his reason said, "Stop. Build a fire. Destroy the fire's fuel, and then hug the ground while the fire passes over you." He was the only man to survive. None of his young firefighters followed his lead. Today, building a firebreak has become standard training procedure because of this incident. But at the time, Captain Dodge's brain created the escape route entirely on its own.

Modern scientific tools, such as the MRI, electronic probes, and EEG, have made it possible to see exactly what the brain does when faced with a choice, a risk, or a dilemma. "Every feeling," Lehrer writes, "is really a summary of data, a visceral response to all of the information that can't be accessed directly" (23). This means that you and I will make better choices if we understand which parts of the brain to access for different tasks, and how to satisfy or tone down conflicting stimuli.

For example, one study asked subjects to memorize a list and report to someone in a room at the end of a hallway. On the way the subjects passed a table where they were invited to take a snack. Those who had a long message to remember — one that required them to remember seven things — usually chose a piece of chocolate cake, while those who only had one or two things to remember tended to take a piece of fruit. The practical application? When the rational brain is working at capacity (and according to psychologist George Miller's essay, "The Magical Number Seven, Plus or Minus Two," memorizing seven things seems to be the capacity), the emotional brain takes over, and the chocolate cake is irresistible. When the rational brain has less to remember, it can overrule emotion and make a wiser choice. No wonder we overeat and fall prey to other temptations when we have too much to do.

So when should we think rationally, and when should we act impulsively? Lehrer ends his book with several practical suggestions.

First, simple problems require reason. When there are few variables to consider, the brain is able to analyze them rationally and provide a reasonable decision. But when the choice contains many variables — as when one is buying a new house — "sleep on it" and then "go with your gut" really is the best advice. Overthinking often leads to poor decision making.

Second, novel problems also require reason. Before reacting intuitively, make sure the brain has enough past experience to help you make the right decision. Creative solutions to new problems require concrete information and rational analysis.

Third, embrace uncertainty. Too often, Lehrer warns, "You are so confident you're right that you neglect all the evidence that contradicts your conclusion." This is especially true in matters such as politics and investment decisions. He offers two solutions: "always entertain competing hypotheses . . . [and] continually remind yourself of what you don't know" (247). Certainty often leads to blindness.

Fourth, you know more than you know. The conscious brain is often unaware of what the unconscious brain knows. "Emotions have a logic all their own," Lehrer says. "They've managed to turn mistakes into educational events" (248–49). The reason superstars like Tom Brady, Tiger Woods, and Renee Fleming can rely on instinct is that they've been there before. Tom Brady has surveyed thousands of football fields and thrown thousands of passes; Tiger Woods has made thousands of putts; Renee Fleming has sung an aria hundreds of times. For them, the brain knows what to do, and thinking just gets in the way.

Fifth, think about thinking. Before making a decision, Lehrer warns, be aware of the kind of decision it is and the kind of thought process it requires. "You can't avoid loss aversion unless you know that the mind treats losses differently than gains," he explains. Knowing how the brain works will help us make better decisions in everything we do.

How We Decide is a book full of real-life stories, scientific experiments, and practical applications. It will help you understand how you make decisions, and will guide you to make better decisions in the future. Returning to Bruce Lee and Ayn Rand's conflict between thinking and feeling, Lehrer makes a strong case for "Think sometimes, feel sometimes. And make sure you know when to do which."

Editor's Note: Review of "How We Decide," by Jonah Lehrer. First Mariner Books edition, 2010 (Harcourt Brace, 2009), 302 pages.

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