INTRODUCTION How do you decide if you can drive through a snowstorm? How high are you willing to climb up a ladder to change a lightbulb? Can you prepare a dinner party for eight? When was the last time you discovered a shortcut through a forest?
For all these challenges, there is only one way to find out. A person needs to devote some time, energy, and physical engagement. Smart talk, texting, virtual goggles, reading, and rationalizing won’t get the job done. The hands have to be on the wheel of the car to learn the feel of slipping tires. The feet need to be balanced on the ladder rungs to detect the tipsiness. The cook has to already know how to chop, fry, and combine four complicated recipes so they are all finished by a certain time. Best of all, finding a shortcut through the forest demands vigilance, courage, and the ability to keep one’s wits, particularly at that moment of self-doubt when the journey seems more like a longcut than a shortcut.
Skills such as these are informed by “physical intelligence”: the components of the mind that allow anyone to engage with and change the world. Inside the brain there is no single module or bit of tissue that makes this possible. Instead, the action-prone mind draws on a multiplicity of capabilities. This book is about these amazing mental operations, how they were discovered, and how they continue to be studied today. Some are almost primordial in their simplicity. How come you don’t walk into walls or off of cliff edges? Others are quite subtle. When you take on a new do-it-yourself project, how much of your problem-solving relies on old habits, winging it, or careful reasoning?
Our psychological intuition about how the brain works inevitably places verbal thought and all the stuff we can talk about, such as our emotions, at the top of the heap. Physical intelligence, which is largely inaccessible to conscious introspection, is treated as a lower form of intelligence, something to be tucked beneath the verbal and largely ignored. This book makes the case that physical intelligence is much more. It is foundational, a kind of knowing that frames much of what the mind spends its time engaged in. Indeed, the very fact that so much of physical intelligence can be performed beyond consciousness is the very design feature that frees a person’s thoughts so he can spend his day thinking about social affairs, work, and the world of ideas. Under all the verbal chatter of the mind, much if not most of what the brain is actually dealing with is the raw physicality of being alive.
For many of my colleagues who study the mind, the very notion that physical action also requires some intelligence draws a blank stare. They focus on thinking and perceiving. Other than ears and eyeballs, the body is largely irrelevant for their kind of science. However, to study a mind without a body ignores some of the greatest pleasures of being alive: experiencing the world directly, as we perform and create. My patients point this out to me time and again. As they lose various physical capacities they also lose bits of their deepest sense of self. One of my patients was a farmer in south Georgia with advancing Parkinson’s disease. There came a sad day when I had to take his driver’s license away. Driving has a way of projecting a person into the physical world, providing a dizzying sense of freedom. For good reason, then, the farmer was severely depressed when he lost his privilege. However, he was not to be deterred. Denied one of his greatest joys, he found an intimidating but satisfactory substitute: he could still drive his oversized bulldozer around his farm. For him, thinking, philosophizing, and reasoning would never offset the sheer joy of getting out and about in his vehicle. Even Stephen Hawking yearned for action. He once commented, “Obviously, because of my disability, I need assistance. But I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have traveled the world, from the Antarctic to zero gravity.”
The hidden nature of physical intelligence poses a problem for the scientist. How can these capacities be exposed for what they are? To a certain degree, all of us are constantly searching for them. We are drawn like moths to a flame whenever we witness physical brilliance, when brain, mind, and body operate together with singular grace, as is sometimes evident in sports, dance, craft, or music. However, a scientist focusing only on superb physical talent can be led astray. It would be as if she were trying to understand language by only studying winners of spelling bees. All of our physical intelligence, not just that of outliers, needs to be explained. Look closely at the barista, the kid playing hopscotch, or the floor mopper and you will soon begin to notice physical brilliance everywhere. To show how and why this brilliance exists, I will dwell on some of my favorite experiments across a wide range of scientific disciplines, including the study of normal infant development, intracranial neurophysiology, robotics, brain scanning, and clinical neurology.
Long ago I discovered that some of the most important components of physical intelligence, the ones that are generalizable and relevant for all of us, are laid bare when one is alone in the natural world, particularly in the wilderness. Venturing into wild places requires enormous ingenuity and resolve. It is the primordial world we originated from as a species, and thus it makes sense that the cognitive capacities that are of greatest value for goal-oriented behavior should come to the forefront there. I make a yearly trip into the wilderness alone. I go to the Sierra Nevada, but one could imagine a similar trip in Alaska, the Rockies, the Cascades, the Okefenokee Swamp, or the great deciduous forests of Appalachia. This book is motivated by one of my trips and some of the capacities of physical intelligence that determined my fate along the way.
A good wilderness trip needs three things for the properties of physical intelligence to be evident. The first is obscurity. Although I had left a map and a detailed itinerary with my wife, I changed my route on the second day of my trip. If anyone went looking for me using the map I had given her, she would probably scour an area that was more than twenty miles away, beyond two glacial divides. Mobile phones don’t work in these parts. And the Park Service is so understaffed, the likelihood of being rescued in a crisis is abysmally low. Without any of these lifelines, a relatively simple hiking trip can suddenly become a profoundly intense and complex experience. The second feature is solitude. On such a trip, there is none of the wonderful chatter and distraction that dominates the closeness and pleasure of an outing with family and friends. Without these entertaining social connections, a solo trip results in an utterly different kind of experience. It is not a lonely one. Rather, the solitude provides time for reflection and an opportunity to examine the kind of intelligence that informed human action as our species evolved. In addition, a trip alone completely changes the stakes and perceived risk. There is no confusion about responsibility. The traveler owns all his or her decisions. Roughness is the third feature. The familiar world is stripped bare; the setting is primordial. The landscape is open and stretches forever, with barely a trace of human influence. For more than 1.3 million years of evolutionary history, this was the ordinary world. There were no level sidewalks, warm houses, or high-rise luxuries. Nothing mitigated risk, eliminated hazards, or minimized effort. Our ancestors evolved in a world that was nothing but wilderness. This landscape endowed our species with remarkable ways of seeing, interpreting, and acting in challenging environs. With that in mind, when I take what are relatively hazardous and unknown explorations into the mountains, I get to experience a very crude simulation of what being alive was like long ago. Survival is paramount and one is ever mindful of it.
We didn’t emerge as a species sitting around. We wandered far and wide, into locales that are almost unimaginable. To really understand physical intelligence, you need to wander. On a previous trip, I climbed one of the southernmost fourteen-thousand-foot peaks of the range I have spent my life roaming in. It was a very long, steep, ten-mile ascent requiring a windswept traverse far above the shelter of trees and running water. Just before the summit, I was surprised to find an obsidian arrowhead. The setting was desolate, remote, and cold. For many scientists, the arrowhead itself would have been critical. The object reveals something about the cultural intelligence of the hunter, his best technology, available resources, and trading network. The object could have been left there two hundred or nine thousand years ago. What interests me is not the specific manufacturing advances revealed by the arrowhead or how big the trading network must have been for it to show up in the region. Rather, it’s the ridiculous location where I found it. The owner probably would have been a Paiute Indian who stalked a deer or mountain goat all the way to the summit, the far side of which ended in cliffs, effectively forming a trap. The hunter had readily climbed through this massive, unforgiving landscape at will, with stunning competence. To me he is amazing not for his technology (a stone-tipped arrow) but for his sustained confidence in stalking, tracking, and climbing over increasingly rough terrain while intensely exposed to sun, wind, or snow. All for dinner. When I roam through the middle of nowhere, the kind of intelligence he and countless generations of ancestors drew on becomes easier to appreciate. The point of my trips, then, is to wander through an environment that makes the natural relationships between thinking and acting obvious to anyone.
To get a good glimpse of what people were like when physical intelligence was honed, one has only to look to the “Iceman,” Ötzi, a mummified hunter who died five thousand years ago just below a high mountain pass on the current Austrian-Italian border. Ötzi’s remains are on display at the Südtiroler Archäologiemuseum in Bolzano, Italy, along with his fur-covered bearskin hat, goatskin clothing, copper-tipped axe, backpack, food scraps, medicine, fire-starting tools, and longbow. Only five feet three inches tall and with an entirely ordinary albeit fit physique, he readily traveled alone and self-sufficiently through the middle of the Alps. He could smelt copper. Take down a large elk. Fabricate Neolithic blades. Travel over glaciers without getting frostbite. He yields a startling view of our past. What we consider to be extraordinary—living in an Alpine wilderness—was entirely ordinary at the time. Ötzi relied on a complex of mental capacities that allowed him to adapt his behavior constantly to meet the demands of an extreme and highly varied environment.
The chapters that follow are a sampling of a few of these capacities—basic properties of the mind that not only kept ancestors like Ötzi alive but continue to manifest themselves in all of us. A common thread running through the chapters is the special role that learning plays in forming this kind of intelligence. The mental capacities that are used for action are, more than anything, different kinds of learning machines that the brain has available for acquiring and maintaining physically derived knowledge. Physical intelligence is absolutely ruthless in requiring that knowledge be gained from direct physical experience. This is profoundly different from, say, the instantaneous remembrance of a face, name, or phone number. Rather, physical intelligence reflects learning processes that constantly tinker with a person’s performance. One never stops learning to cook, to drive, or even to walk, for that matter. It is also a knowledge that is lost from disuse: without practice you will fall on ice or off ladders.
The world Ötzi navigated was physically challenging and complex, characterized by palpable tension arising from an inability to predict what might happen and few means for maintaining control. Here were perfect conditions for improvising, inventing, and enduring some of the most rigorous demands of the wilderness, which lay at the heart of what shaped physical intelligence for eons. Although the wild is uncontrolled, physical intelligence provides the means to establish a sense of control. Humans acquire their skills and learn to solve problems through constant physical experimentation. That was as true for Ötzi as it is for us. There is no end to the sensing, adapting, anticipating, and accommodating that must take place for a person to act intelligently. It takes practice and know-how to do even the little things in life: to stay upright on a slippery sidewalk in front of your home or to know whether you can still climb a ladder without falling off. And most of all, physical intelligence provides the means for experiencing the pure joy of figuring out how to do something for the first time, whether it is building your first campfire or catching your first fish.
Copyright © 2020 by Scott Grafton. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
