How We Learn

by Benedict Carey

  The science itself is what turned me around. Learning science, cognitive psychology, the study of memory—call it what you like. The more I discovered about it, the stronger the urge to do something bigger than a news story. It dawned on me that all these scientists, toiling in obscurity, were producing a body of work that was more than interesting or illuminating or groundbreaking. It was practical, and not only that, it played right into the way I had blossomed as a student all those years ago, when I let go of the reins a bit and widened the margins. I was all over the place in college. I lived in casual defiance of any good study habits and also lived—more so than I ever would have following “good” study habits—with the material I was trying to master. My grades were slightly better than in high school, in much harder courses. In a way, I have been experimenting with that approach ever since.

  The findings from learning science have allowed me to turn my scattered nonstrategy into tactics, a game plan. These findings aren’t merely surprising. They’re specific and useful. Right now. Today. And the beauty is, they can be implemented without spending a whole lot more time and effort and without investing in special classes, tutors, or prep schools.

  In that sense, I see this body of work as a great equalizer. After all, there’s so much about learning that we can’t control. Our genes. Our teachers. Where we live or go to school. We can’t choose our family environment, whether Dad is a helicopter parent or helicopter pilot, whether Mom is nurturing or absent. We get what we get. If we’re lucky, that means a “sensuous education” of the James family variety, complete with tutors, travel, and decades of in-depth, full-immersion learning. If we’re not, then … not.

  About the only thing we can control is how we learn. The science tells us that doing a little here, a little there, fitting our work into the pockets of the day is not some symptom of eroding “concentration,” the cultural anxiety du jour. It’s spaced study, when done as described in this book, and it results in more efficient, deeper learning, not less. The science gives us a breath of open air, the freeing sensation that we’re not crazy just because we can’t devote every hour to laser-focused practice. Learning is a restless exercise and that restlessness applies not only to the timing of study sessions but also to their content, i.e., the value of mixing up old and new material in a single sitting.

  I’ve begun to incorporate learning science into a broad-based theory about how I think about life. It goes like this: Just as modern assumptions about good study habits are misleading, so, too, are our assumptions about bad habits.

  Think about it for a second. Distraction, diversion, catnaps, interruptions—these aren’t mere footnotes, mundane details in an otherwise purposeful life. That’s your ten-year-old interrupting, or your dog, or your mom. That restless urge to jump up is hunger or thirst, the diversion a TV show that’s integral to your social group. You took that catnap because you were tired, and that break because you were stuck. These are the stitches that hold together our daily existence; they represent life itself, not random deviations from it. Our study and practice time needs to orient itself around them—not the other way around.

  That’s not an easy idea to accept, given all we’ve been told. I didn’t trust any of these techniques much at first, even after patting my college self on the back for doing everything (mostly) right. Self-congratulation is too easy and no basis for making life changes. It was only later, when I first began to look closely at the many dimensions of forgetting that my suspicious ebbed. I’d always assumed that forgetting was bad, a form of mental corrosion; who doesn’t?

  As I dug into the science, however, I had to reverse the definition entirely. Forgetting is as critical to learning as oxygen, I saw. The other adjustments followed, with trial and error. For example, I like to finish. Interrupting myself a little early on purpose, to take advantage of the Zeigarnik effect, does not come naturally to me. Unfortunately (or, fortunately) I have no choice. Being a reporter—not to mention a husband, dad, brother, son, and drinking partner—means having to drop larger projects, repeatedly, before having a chance to sit down and complete them. Percolation, then, is a real thing. It happens for me, all the time, and without it I could never have written this book.

  Applying these and other techniques has not made me a genius. Brilliance is an idol, a meaningless projection, not a real goal. I’m continually caught short in topics I’m supposed to know well, and embarrassed by what I don’t know. Yet even that experience smells less of defeat than it once did. Given the dangers of fluency, or misplaced confidence, exposed ignorance seems to me like a cushioned fall. I go down, all right, but it doesn’t hurt as much as it once did. Most important, the experience acts as a reminder to check and recheck what I assume I know (to self-test).

  The science of learning is not even “science” to me anymore. It’s how I live. It’s how I get the most out of what modest skills I’ve got. No more than that, and no less.

  I will continue to follow the field. It’s hard not to, once you see how powerful the tools can be—and how easily deployed. The techniques I’ve laid out here are mostly small alterations that can have large benefits, and I suspect that future research will focus on applications. Yes, scientists will surely do more basic work, perhaps discovering other, better techniques and more complete theories. The clear value of what’s already there, however, begs for an investigation into how specific techniques, or combinations, suit specific topics. “Spaced interleaving” may be the best way to drive home math concepts, for instance. Teachers might begin to schedule their “final” exam for the first day of class, as well as the last. Late night, mixed-drill practice sessions could be the wave of the future to train musicians and athletes. Here’s one prediction I’d be willing to bet money on: Perceptual learning tools will have an increasingly central role in advanced training—of surgeons and scientists, as well as pilots, radiologists, crime scene investigators, and more—and perhaps in elementary education as well.

  Ultimately, though, this book is not about some golden future. The persistent, annoying, amusing, ear-scratching present is the space we want to occupy. The tools in this book are solid, they work in real time, and using them will bring you more in tune with the beautiful, if eccentric, learning machine that is your brain. Let go of what you feel you should be doing, all that repetitive, overscheduled, driven, focused ritual. Let go, and watch how the presumed enemies of learning—ignorance, distraction, interruption, restlessness, even quitting—can work in your favor.

  Learning is, after all, what you do.

  Appendix

  Eleven Essential Questions

  Q: Can “freeing the inner slacker” really be called a legitimate learning strategy?

  A: If it means guzzling wine in front of the TV, then no. But to the extent that it means appreciating learning as a restless, piecemeal, subconscious, and somewhat sneaky process that occurs all the time—not just when you’re sitting at a desk, face pressed into a book—then it’s the best strategy there is. And it’s the only one available that doesn’t require more time and effort on your part, that doesn’t increase the pressure to achieve. If anything, the techniques outlined in this book take some of the pressure off.

  Q: How important is routine when it comes to learning? For example, is it important to have a dedicated study area?

  A: Not at all. Most people do better over time by varying their study or practice locations. The more environments in which you rehearse, the sharper and more lasting the memory of that material becomes—and less strongly linked to one “comfort zone.” That is, knowledge becomes increasingly independent of surroundings the more changes you make—taking your laptop onto the porch, out to a café, on the plane. The goal, after all, is to be able to perform well in any conditions.

  Changing locations is not the only way to take advantage of the so-called context effect on learning, however. Altering the time of day you study also helps, as does changing how you engage the material, by reading or discussing, typ
ing into a computer or writing by hand, reciting in front of a mirror or studying while listening to music: Each counts as a different learning “environment” in which you store the material in a different way.

  Q: How does sleep affect learning?

  A: We now know that sleep has several stages, each of which consolidates and filters information in a different way. For instance, studies show that “deep sleep,” which is concentrated in the first half of the night, is most valuable for retaining hard facts—names, dates, formulas, concepts. If you’re preparing for a test that’s heavy on retention (foreign vocabulary, names and dates, chemical structures), it’s better to hit the sack at your usual time, get that full dose of deep sleep, and roll out of bed early for a quick review. But the stages of sleep that help consolidate motor skills and creative thinking—whether in math, science, or writing—occur in the morning hours, before waking. If it’s a music recital or athletic competition you’re preparing for, or a test that demands creative thinking, you might consider staying up a little later than usual and sleeping in. As discussed in chapter 10: If you’re going to burn the candle, it helps to know which end to burn it on.

  Q: Is there an optimal amount of time to study or practice?

  A: More important than how long you study is how you distribute the study time you have. Breaking up study or practice time—dividing it into two or three sessions, instead of one—is far more effective than concentrating it. If you’ve allotted two hours to mastering a German lesson, for example, you’ll remember more if you do an hour today and an hour tomorrow, or—even better—an hour the next day. That split forces you to reengage the material, dig up what you already know, and re-store it—an active mental step that reliably improves memory. Three sessions is better still, as long as you’re giving yourself enough time to dive into the material or the skills each time. Chapter 4 explores why spacing study time is the most powerful and reliable technique scientists know of to deepen and extend memory.

  Q: Is cramming a bad idea?

  A: Not always. Cramming works fine as a last resort, a way to ramp up fast for an exam if you’re behind and have no choice. It’s a time-tested solution, after all. The downside is that, after the test, you won’t remember a whole lot of what you “learned”—if you remember any at all. The reason is that the brain can sharpen a memory only after some forgetting has occurred. In this way, memory is like a muscle: A little “breakdown” allows it to subsequently build greater strength. Cramming, by definition, prevents this from happening.

  Spaced rehearsal or study (see previous question) or self-examination (see next question) are far more effective ways to prepare. You’ll remember the material longer and be able to carry it into the next course or semester easily. Studies find that people remember up to twice as much of material that they rehearsed in spaced or tested sessions than during cramming. If you must cram, do so in courses that are not central to your main area of focus.

  Q: How much does quizzing oneself, like with flashcards, help?

  A: A lot, actually. Self-testing is one of the strongest study techniques there is. Old-fashioned flashcards work fine; so does a friend, work colleague, or classmate putting you through the paces. The best self-quizzes do two things: They force you to choose the right answer from several possibilities; and they give you immediate feedback, right or wrong. As laid out in chapter 5, self-examination improves retention and comprehension far more than an equal amount of review time. It can take many forms as well. Reciting a passage from memory, either in front of a colleague or the mirror, is a form of testing. So is explaining it to yourself while pacing the kitchen, or to a work colleague or friend over lunch. As teachers often say, “You don’t fully understand a topic until you have to teach it.” Exactly right.

  Q: How much does it help to review notes from a class or lesson?

  A: The answer depends on how the reviewing is done. Verbatim copying adds very little to the depth of your learning, and the same goes for looking over highlighted text or formulas. Both exercises are fairly passive, and can cause what learning scientists call a “fluency illusion”: the impression that, because something is self-evident in the moment, it will remain that way in a day, or a week. Not necessarily so. Just because you’ve marked something or rewritten it, digitally or on paper, doesn’t mean your brain has engaged the material more deeply. Studying highlighted notes and trying to write them out—without looking—works memory harder and is a much more effective approach to review. There’s an added benefit as well: It also shows you immediately what you don’t know and need to circle back and review.

  Q: There’s so much concern that social media and smart-phones and all manner of electronic gadgets are interfering with learning—and even changing the way people think. Is this merited? Is distraction always bad?

  A: No. Distraction is a hazard if you need continuous focus, like when listening to a lecture. But a short study break—five, ten, twenty minutes to check in on Facebook, respond to a few emails, check sports scores—is the most effective technique learning scientists know of to help you solve a problem when you’re stuck. Distracting yourself from the task at hand allows you to let go of mistaken assumptions, reexamine the clues in a new way, and come back fresh. If you’re motivated to solve the problem—whether it’s a proof, an integral, or a paragraph you just can’t get right—your brain will continue to work on it during the break off-line, subconsciously, without the (fixated, unproductive) guidance you’ve been giving it. The evidence on this is discussed in chapter 6.

  Q: Is there any effective strategy for improving performance on longer-term creative projects?

  A: Yes. Simply put: Start them as early as possible, and give yourself permission to walk away. Deliberate interruption is not the same as quitting. On the contrary, stopping work on a big, complicated presentation, term paper, or composition activates the project in your mind, and you’ll begin to see and hear all sorts of things in your daily life that are relevant. You’ll also be more tuned into what you think about those random, incoming clues. This is all fodder for your project—it’s interruption working in your favor—though you do need to return to the desk or drafting table before too long. The main elements in this “percolation” process are detailed in chapter 7.

  Q: What’s the most common reason for bombing a test after what felt like careful preparation?

  A: The illusion that you “knew” something well just because it seemed so self-evident at the time you studied it. This is what learning scientists call “fluency,” the assumption that because something is well known now it will remain that way. Fluency illusions form automatically and subconsciously. Beware study “aids” that can reinforce the illusion: highlighting or rewriting notes, working from a teacher’s outline, restudying after you’ve just studied. These are mostly passive exercises, and they enrich learning not at all. Making your memory work a little harder—by self-quizzing, for example, or spacing out study time—sharpens the imprint of what you know, and exposes fluency’s effects.

  Q: Is it best to practice one skill at a time until it becomes automatic, or to work on many things at once?

  A: Focusing on one skill at a time—a musical scale, free throws, the quadratic formula—leads quickly to noticeable, tangible improvement. But over time, such focused practice actually limits our development of each skill. Mixing or “interleaving” multiple skills in a practice session, by contrast, sharpens our grasp of all of them. This principle applies broadly to a range of skills, and can be incorporated into daily homework or practice—by doing a geometry proof from early in the term, for example, or playing arpeggios you learned years ago, or intermingling artistic styles in studying for an art history class. This kind of mixing not only acts as a review but also sharpens your discrimination skills, as described in Chapter 8. In a subject like math, this is enormously helpful. Mixed-problem sets—just adding one or two from earlier lessons—not only reminds you what you’ve learned but also trains you to ma
tch the problem types with the appropriate strategies.

  For my parents

  Acknowledgments

  Writing a book is one part lonely effort and two parts group therapy, and I am forever grateful to those who provided the latter. To Kris Dahl, my exuberantly effective agent, and to Andy Ward, my editor, an exacting collaborator who forced me to think through the ideas in this book more clearly and deeply—the best company anyone could have. I owe a great debt to Barbara Strauch at The New York Times for years of support and advice, and my colleagues at the Science Times. I thank Rick Flaste for seeing (decades ago) that behavior was a beat worth covering and for bringing me to a great newspaper that continues to cover scientific research in depth.

  My work has allowed me access to the many scientists who provided the bones of this book. Among them, I am grateful to Suzanne Corkin, Michael Gazzaniga, Daniel Willingham, Philip Kellman, Steven Smith, Doug Rohrer, Matt Walker, Henry Roediger III, Harry Bahrick, Ronda Leathers Dively, the great Todd Sacktor, and especially Robert and Elizabeth Ligon Bjork, who reviewed large portions of the manuscript and helped me understand the most difficult pockets of the science. I am also in debt to the staff at Columbia University’s Social Work Library and the University of Colorado’s Library for Research Assistance. Any mistakes that remain in the text are all mine.