The Extended Mind: The Power of Thinking Outside the Brain

Book Preface

WHEN YOU’RE WRITING a book about how to think well, your sources—the cognitive scientists, psychologists, biologists, neuroscientists, and philosophers who all have something to contribute on the subject—will often seem to be speaking, via their work, directly to you: Yes, you there, writing a book! They cajole and insist, they argue and debate, they issue warnings and pass judgment; as you lay out their recommendations for the reader, they inquire pointedly: Are you taking your own advice?

I entered into one such intimate exchange when I read, with a jolt of recognition, a passage written more than 130 years ago; it was as if the author were reaching through the pages that lay open on my desk. Making the meeting more intense, the writer in question was a distinctly intimidating character: the German philosopher Friedrich Nietzsche, he of the severe gaze and vaguely sinister mustache.

“How quickly we guess how someone has come by his ideas,” Nietzsche slyly observed, “whether it was while sitting in front of his inkwell, with a pinched belly, his head bowed low over the paper—in which case we are quickly finished with his book, too! Cramped intestines betray themselves—you can bet on that—no less than closet air, closet ceilings, closet narrowness.”

The room in which I was writing suddenly seemed rather airless and small.

I encountered his words as I was working on a chapter about how bodily movement affects the way we think. The quote from Nietzsche appears in a book titled A Philosophy of Walking, by the contemporary French philosopher Frédéric Gros; Gros has his own thoughts to add. Don’t think of a book as issuing only from an author’s head, he advises. “Think of the scribe’s body: his hands, his feet, his shoulders and legs. Think of the book as an expression of physiology. In all too many books the reader can sense the seated body, doubled up, stooped, shriveled in on itself.”

My seated body shifted guiltily in its chair, which it had occupied all morning.

Far more conducive to the act of creation, Gros continues, is “the walking body”—which, he says, is “unfolded and tensed like a bow: opened to wide spaces like a flower to the sun.” Nietzsche, he reminds us, wrote that we should “sit as little as possible; do not believe any idea that was not born in the open air and of free movement.”

The philosophers were ganging up on me; I closed my laptop and went for a walk.

I was acting not only on their say-so, of course; by this point in my research I had read dozens of empirical studies showing that a bout of physical activity sharpens our attention, improves our memory, and enhances our creativity. And in fact, I found that the forward movement of my legs, the flow of images past my eyes, the slight elevation of my heart rate did work some kind of change on my mind. Upon sitting back down at my desk, I wasted no time resolving a knotty conceptual problem that had tormented me all morning. (I can only hope that the prose I produced also “retains and expresses the energy, the springiness of the body,” in Gros’s formulation.) Could my brain have solved the problem on its own, or did it require the assist provided by my ambulatory limbs?

Our culture insists that the brain is the sole locus of thinking, a cordoned-off space where cognition happens, much as the workings of my laptop are sealed inside its aluminum case. This book argues otherwise: it holds that the mind is something more like the nest-building bird I spotted on my walk, plucking a bit of string here, a twig there, constructing a whole out of available parts. For humans these parts include, most notably, the feelings and movements of our bodies; the physical spaces in which we learn and work; and the other minds with which we interact—our classmates, colleagues, teachers, supervisors, friends. Sometimes all three elements come together in especially felicitous fashion, as they did for the brilliant intellectual team of Amos Tversky and Daniel Kahneman. The two psychologists carried out much of their groundbreaking work on heuristics and biases—the human mind’s habitual shortcuts and distortions—by talking and walking together, through the bustling streets of Jerusalem or along the rolling hills of the California coast. “I did the best thinking of my life on leisurely walks with Amos,” Kahneman has said.

Many tomes have been written on human cognition, many theories proposed and studies conducted (Tversky and Kahneman’s among them). These efforts have produced countless illuminating insights, but they are limited by their assumption that thinking happens only inside the brain. Much less attention has been paid to the ways people use the world to think: the gestures of the hands, the space of a sketchbook, the act of listening to someone tell a story, or the task of teaching someone else. These “extra-neural” inputs change the way we think; it could even be said that they constitute a part of the thinking process itself. But where is the chronicle of this mode of cognition? Our scientific journals mostly proceed from the premise that the mental organ is a disembodied, placeless, asocial entity, a “brain in a vat”; our history books spin tales that attribute world-changing breakthroughs to individual men, thinking great thoughts on their own. Yet a parallel narrative has existed in front of us all along—a kind of secret history of thinking outside the brain. Scientists, artists, authors; leaders, inventors, entrepreneurs: they’ve all used the world as raw material for their trains of thought. This book aims to exhume that hidden saga, reclaiming its rightful place in any full accounting of how the human race has achieved its remarkable feats of intellect and creativity.

We’ll learn about how geneticist Barbara McClintock made her Nobel Prize–winning discoveries by imaginatively “embodying” the plant chromosomes she studied, and about how pioneering psychotherapist and social critic Susie Orbach senses what her patients are feeling by tuning in to the internal sensations of her own body (a capacity known as interoception). We’ll contemplate how biologist James Watson determined the double-helix structure of DNA by physically manipulating cardboard cutouts he’d made himself, and how author Robert Caro plots the lives of his biographical subjects on an intricately detailed wall-sized map. We’ll explore how virologist Jonas Salk was inspired to complete his work on a polio vaccine while wandering a thirteenth-century Italian monastery, and how the artist Jackson Pollock set off a revolution in painting by trading his apartment in frenetic downtown Manhattan for a farmhouse on the verdant south fork of Long Island. We’ll find out how Pixar director Brad Bird creates modern movie classics like Ratatouille and The Incredibles by arguing—vehemently—with his longtime producer, and how physicist Carl Wieman, another Nobel Prize winner, figured out that inducing his students to talk with one another was the key to getting them to think like scientists.

Such stories push back against the prevailing assumption that the brain can, or should, do it all on its own; they are vivid testimony to the countervailing notion that we think best when we think with our bodies, our spaces, and our relationships. But as with Friedrich Nietzsche’s commendation of the virtues of walking, the evidence supporting the efficacy of thinking outside the brain is far from merely anecdotal. Research emerging from three related areas of investigation has convincingly demonstrated the centrality of extra-neural resources to our thinking processes.

First, there is the study of embodied cognition, which explores the role of the body in our thinking: for example, how making hand gestures increases the fluency of our speech and deepens our understanding of abstract concepts. Second, there is the study of situated cognition, which examines the influence of place on our thinking: for instance, how environmental cues that convey a sense of belonging, or a sense of personal control, enhance our performance in that space. And third, there is the study of distributed cognition, which probes the effects of thinking with others—such as how people working in groups can coordinate their individual areas of expertise (a process called “transactive memory”), and how groups can work together to produce results that exceed their members’ individual contributions (a phenomenon known as “collective intelligence”).

As a journalist who has covered research in psychology and cognitive science for more than twenty years, I read the findings generated by these fields with growing excitement. Together they seemed to indicate that it’s the stuff outside our heads that makes us smart—a proposition with enormous implications for what we do in education, in the workplace, and in our everyday lives. The only problem: there was no “together,” no overarching framework that organized these multitudinous results into a coherent whole. Researchers working within these three disciplines published in different journals and presented at different conferences, rarely drawing connections among their areas of specialization. Was there some unifying idea that could pull together these deeply intriguing findings?

Once again a philosopher came to my rescue: this time it was Andy Clark, professor of cognitive philosophy at the University of Sussex in England. In 1995 Clark had co-written a paper titled “The Extended Mind,” which opened with a deceptively simple question: “Where does the mind stop and the rest of the world begin?” Clark and his coauthor, philosopher David Chalmers, noted that we have traditionally assumed that the mind is contained within the head—but, they argued, “there is nothing sacred about skull and skin.” Elements of the world outside may effectively act as mental “extensions,” allowing us to think in ways our brains could not manage on their own.

Clark and Chalmers initially focused their analysis on the way technology can extend the mind—a proposal that quickly made the leap from risibly preposterous to self-evidently obvious, once their readers acquired smartphones and began offloading large chunks of their memories onto their new devices. (Fellow philosopher Ned Block likes to say that Clark and Chalmers’s thesis was false when it was written in 1998 but subsequently became true—perhaps in 2007, when Apple introduced the first iPhone.)

Yet as early as that original paper, Clark hinted that other kinds of extensions were possible. “What about socially extended cognition?” he and Chalmers asked. “Could my mental states be partly constituted by the states of other thinkers? We see no reason why not.” In the years that followed, Clark continued to enlarge his conception of the kinds of entities that could serve as extensions of the mind. He observed that our physical movements and gestures play “an important role in an extended neural-bodily cognitive economy”; he noted that humans are inclined to create “designer environments”—carefully appointed spaces “that alter and simplify the computational tasks which our brains must perform in order to solve complex problems.” Over the course of many more published papers and books, Clark mounted a broad and persuasive argument against what he called the “brainbound” perspective—the view that thinking happens only inside the brain—and in favor of what he called the “extended” perspective, in which the rich resources of our world can and do enter into our trains of thought.

Consider me a convert. The notion of the extended mind seized my imagination and has not yet released its grip. During my many years of reporting, I had never before encountered an idea that changed so much about how I think, how I work, how I parent, how I navigate everyday life. It became apparent to me that Andy Clark’s bold proposal was not (or not only!) the esoteric thought experiment of an ivory tower philosopher; it was a plainly practical invitation to think differently and better. As I began to catalog the dozens of techniques for thinking outside the brain that researchers have tested and verified, I eagerly incorporated them into my own repertoire.

These include methods for sharpening our interoceptive sense, so as to use these internal signals to guide our decisions and manage our mental processes; they encompass guidelines for the use of specific types of gesture, or particular modes of physical activity, to enhance our memory and attention. This research offers instructions on using time in nature to restore our focus and increase our creativity, as well as directions for designing our learning and working spaces for greater productivity and performance. The studies we’ll cover describe structured forms of social interaction that allow other people’s cognition to augment our own; they also supply guidance on how to offload, externalize, and dynamically interact with our thoughts—a much more effective approach than doing it all “in our heads.”

In time I came to recognize that I was acquiring a second education—one that is increasingly essential but almost always overlooked in our focus on educating the brain. Over many years of elementary school, high school, and even college and graduate school, we’re never explicitly taught to think outside the brain; we’re not shown how to employ our bodies and spaces and relationships in the service of intelligent thought. Yet this instruction is available if we know where to look; our teachers are the artists and scientists and authors who have figured out these methods for themselves, and the researchers who are, at last, making these methods the object of study.

For my own part, I’m convinced that I could not have written this book without the help of the practices detailed within it. That’s not to say that I didn’t sometimes fall back into our culture’s default position. Before Friedrich Nietzsche’s fortuitous intervention that morning, I was in full brainbound mode, my “head bowed low” over my keyboard, working my poor brain ever harder instead of looking for opportunities to extend it. I’m grateful for the nudge my research supplied; it’s that gentle push in a more productive direction that this book seeks to offer its own readers.

Frédéric Gros, the French philosopher who brought Nietzsche’s words to my attention, maintains that thinkers ought to get moving in a “quest for a different light.” As he observes, “Libraries are always too dark,” and books written among the stacks manifest this dull dimness—while “other books reflect piercing mountain light, or the sea sparkling in sunshine.” It’s my hope that this book will cast a different light, bring a bracing gust of fresh air to the thinking we do as students and workers, as parents and citizens, as leaders and creators. Our society is facing unprecedented challenges, and we’ll need to think well in order to solve them. The brainbound paradigm now so dominant is clearly inadequate to the task; everywhere we look we see problems with attention and memory, with motivation and persistence, with logical reasoning and abstract thinking. Truly original ideas and innovations seem scarce; engagement levels at schools and in companies are low; teams and groups struggle to work together in an effective and satisfying way.

I’ve come to believe that such difficulties result in large part from a fundamental misunderstanding of how—and where—thinking happens. As long as we settle for thinking inside the brain, we’ll remain bound by the limits of that organ. But when we reach outside it with intention and skill, our thinking can be transformed. It can become as dynamic as our bodies, as airy as our spaces, as rich as our relationships—as capacious as the whole wide world