In the Beginning
A Wandering Pond Snail
A piece of chalk flies from the hand of the schoolmaster and misses the boy asleep at the back of class 5M by a good six inches. The rest of the boys chuckle. The boy asleep is a chubby 11-year-old with dark hair. He is in the M stream, the bottom tier at Colet Court School in London. M does not stand for moron, as the other boys in the school would have it; it stands for mediocre. The teacher is Mr. Lewison, six foot two inches tall, young, with long shoulder-length brown hair; he was once a top graduate from Cambridge University. Again, he takes aim and fires another piece of chalk at the boy. Mr. Lewison’s double major was in English and psychology, not chalk throwing. The second piece of chalk misses the boy’s left ear. The rest of the class laughs. The third piece hits the center of the boy’s forehead; I wake up. “Levine, welcome back to Julius Caesar,” Mr. Lewison calls across the room. “Come and see me at the end of class.” If ever there was a chair comfortable enough to sit in and a lesson boring enough to fall asleep in, Mr. Lewison’s 5M English class was it. But it was not Mr. Lewison’s fault entirely that I repeatedly fell asleep; I had not had an uninterrupted night’s sleep for months. I didn’t sleep a whole night through because I was infatuated by Joanne.
I cannot explain quite how I became infatuated with Joanne at the age of 11. It is a natural age for a boy to feel yearnings of the heart since by then hormones have begun their campaign. But it was not girls that dominated my nights and dreams. My heart had been stolen by Joanne Lymnaeidae—a pond snail.
Love is a strange mistress, and I must confess that I was not monogamous; two snails possessed my devotion, Joanne and Maurice, both acquired from the lake in Regents Park. Worse still, there were other snails before Maurice and Joanne, but we will not discuss their fates. Suffice it to say, snail-rearing is an art form that takes several snails to master. (If snail love strikes you too, one trick of the trade I will share is that cats view pond snails that live under your bed as a delicacy.)
What’s an 11-year-old boy doing with snails? Over several weeks I had spent my allowance on building a large, thin fish tank. It was about three feet long, two feet tall, but only four inches wide. I had bought each piece of glass from a local glazier and joined them together with silicone glue. The tank constantly leaked water, but not badly. Each night at just before 9 p.m. (bedtime) I would remove either Joanne or Maurice from bowls under my bed and attach her/him (they are hermaphroditic) to the inside of the tank. Once the snail attached, I would mark the spot with a thick red marker on the outside of the glass. Then I set my alarm clock for an hour later, for 10 p.m. At 10 p.m., I woke up and marked where the snail had moved to, and then I set my alarm for 11 p.m. and went back to sleep. I woke up at 11 p.m., marked the snail’s progress and reset the alarm for midnight. I did this every hour through the night until 7 a.m. At 7 a.m. I traced the red markings onto parchment paper, dated the paper and replaced the snail under my bed. I did this every night for two years, working with many new loves: many other snails.
I told Mr. Lewison about my snail-tracking project. “What on earth are you doing this for?” Mr. Lewison asked me after class. I explained that I had a theory that each snail advanced with a fixed pattern of movement unique to it. I believed that each snail was wired to move in a certain way—that every snail has a certain predefined style of motion. I hypothesized that Joanne would always move in swirls, whereas Maurice would always slime along in straight lines.
“And do they?” the chalk-flinging master asked.
At that point, I was only a few months in to my experiments, so I told him I did not know.
Mr. Lewison was a young, dynamic teacher who wanted to be viewed as cool by the students, before being cool was cool. “You need to focus on your schoolwork,” he told me, but he did not tell me to stop my experiments. I knew that I baffled Mr. Lewison. He had overseen the IQ testing of the entire school year. My score was the highest by 20 points, but I was in the M stream, and I seemed to him as dim as a piece of chalk. He could not figure me out; I kept falling asleep in his English class, and he kept throwing chalk at me. I was consistently second from the bottom. He never asked me about the snails again.
19 Snails Later
I finished my experiments two years later, and, at the age of 13, I was interviewed to enter one of London’s most famous schools, St. Paul’s. St. Paul’s is a classic old British school. It had spawned colonels, senior civil servants and leaders. I showed up with 217 three-foot pieces of parchment paper—each was the overnight pattern of movement from a single snail. The principal of the school, Mr. Hyde, was a thin, wiry man in a dark suit. He looked as if he should be unpleasant (St. Paul’s, at that time, used the cane for discipline), but he was not. Mr. Hyde was genuinely interested in the education of his students; he just beat bad behavior out of them. I remember the noise of the pieces of parchment paper shaking in my sweaty hand as I explained my experiments to Mr. Hyde.
“Were you right about your theory?” he asked me.
By then I knew the answer. I explained to him that I was sort of right and kind of wrong. I had originally thought that every snail would move with its own swirl and at a constant distance every night. In that regard I had been wrong. But I was right in another way—each snail had a distinct style of movement. Joanne, for instance, always moved in a jagged way—in the pattern of saw teeth—while Maurice consistently moved across the glass smoothly as if following the curve of a shooting star.
Mr. Hyde asked me why I thought that was, and I explained, like a typical scientist, that I would need to undertake further research. My initial bedroom studies trying to dissect pieces of snail brain had not been successful (cat food). I did not tell him this, but I guessed the style of snail movement was hardwired in their brains. No doubt bemused by the snail boy with a surprisingly high IQ, Mr. Hyde admitted me to St. Paul’s, and a year later I was awarded the St. Paul’s Smee Prize in Science—the youngest boy ever to get it.
I never explained to Mr. Hyde or to Mr. Lewison why my IQ score was so high, but I’ll tell you. Mr. Lewison had told us the Friday before that on Tuesday the entire school year was having IQ testing. It was long before the Internet; I went to the Westminster Public Library, which housed one of London’s largest medical libraries. I had been there several times to consult manuals about snail anatomy (Playboy to a snail lover). The library had a ledger-sized book, about two feet long, that contained all the age-adjusted state-approved IQ tests for UK schools. The first test I attempted from the book gave me an IQ of 105. I spent the entire weekend going through those tests again and again; by Sunday night I was averaging above 120. The IQ test Mr. Lewison gave us was identical to one in the book. One mystery solved.
It would take 34 years for me to solve the mystery of moving snails, but from age 11 on, I was obsessed by why things move. Science, I now realize, never discovers new things but only uncovers the secrets of nature. The patterns of movement had been established in the brains of my snails long before I studied them. But I’ll tell you that experimenting—being a scientist—is the coolest thing in the world. Every day is an adventure into the unknown.
From Wandering Pond Snails to Motionless Worms
Clad in an immaculate white coat, Cheng Huang leans over a petri dish balanced on a microscope. He has a needle pinched tightly between his thumb and index finger. Staring down the microscope eyepieces, he watches a tiny worm on the palm-size petri dish. It wiggles across the nutrient-rich agar. He picks up the next petri dish. This worm lies still. With the needle tip he carefully prods the motionless worm. It curls in response—it is not dead. Soon it will die and not respond to the prod of the needle. For these worms and the 1,400 others in the experiment, just as for humans, movement defines life. Stillness is death.
The worms, Cheng and his colleagues discovered,1 have specific genes that predetermine their transition from wriggling freely, to prod responsive, to still death. Genes program the transition of these simple worms from madly wriggly infant worms to still dead ones. The worms follow a genetic road map that charts the frenzied movement of youth, to slowly aging, to death. These genes are mirrored in fish, horses, nonhuman primates and humans. Movement is a programmatic part of life, as natural as breathing.
Death Rattle
My first internship as a third-year medical student was at a small regional hospital north of London. One night, a 92-year-old woman was brought into the emergency room in respiratory arrest. She was gaunt and white. Her skin was cool. She had no respiration and I could not feel a pulse. We were about to call her time of death when her left wrist flickered and her fingers twitched—a single tiny movement, nothing else. This was long before the HIV and hepatitis epidemics, and I quickly started mouth-to-mouth resuscitation. The lady came around. It was that tiny movement that defined her as being alive.
Studies document that people move with natural rhythms throughout their lives. Think of newborn babies thrashing their arms and legs. Scientists used to argue that frenetic and disordered baby movements were wasting energy.2 The new thinking is different; these early thrashing, wild movements are the stimuli that the limbs need to develop and for the brain to learn how to control them.3 In fact, in premature brain-injured babies with stunted early development, therapists use Kinesthetic Stimulation Therapy, in which they move the tiny limbs to force the brain to reconnect and thrash baby style.4
Most newborns begin to sit at six months, try to pull themselves up by nine months and walk by two years. In fact, children who do not meet these milestones require a second look from the medical teams. The progression of early movement is so intricately programmed that it is predictable.5
Recently I went to the post office to send some packages abroad. In line in front of me was an elderly couple; the man had a cane; the woman, a slow, wide gait. The man with the cane stood just as still as the white-haired woman beside him. As people were helped, the couple shuffled forward. In front of this quiet pair was a father who was constantly screaming at his son and daughter, aged about six and eight. They could not stand still, even for a minute. One knocked over a pile of forms. “Isabella!” her father shouted. Some might claim that these children were badly behaved, but those of us who are parents know that children just can’t help it. As I have watched my own children grow up, I can attest to the constant, never-ceasing movement of the six-year-old and the progressive shift in activity levels as children age. Adults move less than children—consider parents sitting on the bleachers as their children play sports. Then we age and become slower still. Like the elderly couple in front of me in the post office line, we zip around less and become more careful and studied with our movements. And eventually, when we stop moving, death casts its shadow.6
From birth through death there is a predictable, programmed timetable of movement. We transition from the frenetic nature of childhood, to the organized movement of adulthood, through the stillness of aging. Movement is not only the essence of life; it is the rhythm that defines our stage of living. Is it any wonder that compressing a moving body into a chair for decade after decade does it harm?
Moving Humans: Sapiens sans Sedentary
Homo sapiens evolved over 2 million years to the drumbeat of natural selection. Natural selection is the process whereby tiny modifications in the DNA result in the body performing better to create a selection advantage. If two people are being chased by a saber-toothed tiger, and one is genetically a tiny bit faster, that person will escape and live to procreate. The slower person lags behind and gets eaten—yum.
Over 2 million years, human beings evolved from knuckle-brushing apelike forms that lived in the forests of Africa to the upright Homo sapiens of today.
A Love Story
As humans evolved from tree-climbing forest-dwelling apes, they left the forests. Imagine two girl apes. Stefanie is an oddity; she has a genetic mutation that causes her to have a straight, stiff spine and walk upright, whereas Zoe is a traditional back-bent knuckle walker. Zoe climbs and swings from tree to tree more adeptly than stiff-backed Stefanie. As a result, Zoe gets the best tree nest, the hottest guy-ape and the best food. But stiff-backed Stefanie, disgruntled and alone, stands taller than Zoe and sees that there is a world of swishing grasses beyond the forest. Off Stefanie goes, beyond the confines of the forest, in search of food. Since there are no other apes there, she finds food aplenty. The good news for us is that when stiff-backed Stefanie ventured onto the plains of Africa, she also spotted across the swishing grass stiff-backed, uprightly mobile Stan (who had the same stiff-back genetic mutation). It was love at first sight. Because both Stefanie and Stan had the stiff-back mutation, their baby apes got it too and stood tall. That is how one genetic mutation can dramatically impact movement. In case you think that this is a ridiculous example, there is, in fact, a human syndrome originally called Stiffman Syndrome and now called Stiff Person Syndrome (yes, really!) that can be accounted for by a gene mutation.7
The other thing we learn from stiff-backed Stefanie and Stan is the interplay between environment and genes. If Stefanie and Stan had stayed in the forest rather than venturing out onto the grass-swishing plains, unable to climb, they would have not eaten and would have become emaciated, infertile, and would have died. It was the availability of the plains plus the behaviors of Stefanie and Stan that took them out of the forest to make glorious love, nourish and explore.
The issue of how behavior, genes and environment interact is the new wave in science. I have described the stiff-back gene and how it propelled Stan into Stephanie’s arms. Now imagine that a second gene comes into play, the risk-taker gene. If you are an ape swinging through the trees, having the risk-taker gene is a bad thing. You swing for a branch that is too far away, and kerplonk! You are ape jelly on the forest floor.
Let us now examine the risk-taker gene in Stefanie and Stan’s four children—Jilly, Jonny, Bert and Beatrice—living on the plains. All four of them had the stiff-back gene and stand erect.
Jilly and Jonny do not have the risk-taker gene. One day they are playing in the plains and venture to the edge of the forest. There they meet our old friend the tree-swinging forest ape, Zoe. “What are you guys doing out of the forest?” Zoe asks. “Apes belong in the forest. Come back and join the community.” Jilly and Jonny see hordes of apes swinging through the forest. They have no risk-taker gene, and so they are genetically compliant. They follow Zoe into the forest. Their fate is sad. Because they have the stiff-back gene, they do not climb so well. Soon they are hungry and weak, and from far above in the forest canopy, Zoe watches them die. She has a mean smile on her face—for Zoe is genetically a conformist (no risk-taker gene) and resents anyone different from her.
In contrast, brother Bert and sister Beatrice have the risk-taker gene. They are explorers. Because they have this genetic defect, they never venture back to the forest edge—they are genetically programmed to explore. They go farther than their parents ever went, and slowly and surely they and then their children make their way out of Africa to the new world beyond. They and their progeny become the new humans. Again, if you think this is a ridiculous concept, genes have been identified that indeed predict participating in high-risk behaviors.8 What is more fascinating is that similar brain genes predict whether a person will participate in active leisure activities in our modern chair-sentenced world.9
So here in this love story of stiff-backed Stefanie and Stan we see:
We have examined the effects of just two genes. Now imagine how 21,000 genes might interact—because that’s how many we have.
Stiff-Backed Humans Walked across the Earth
Early apes became early humans, so-called early Homo.10 Early Homo evolved until they ceased to walk in a knuckle-dusting fashion and stood erect. The skeletons from the five Dmanisi skulls, from the Republic of Georgia, showed that these first Homos were short, and their legs enabled them to walk for long distances as fully upright bipeds. As the newer humans became progressively more erect, they spread across the world over 2 million years, not in cars or by airplanes but on foot; the more they evolved, the farther they walked. The new world was filled by people who walked.
Over the 2 million years that the human body evolved to walk, so too the human brain evolved to control it. Human thinking evolved from the human brain. Thoughts flow and ebb, as do the sweeps of arms and legs; dynamic bodies are dynamic minds.
Humans evolved over 2 million years to cultivate their new world. They did this walking. They built social collectives. They built shelters for their children with their dynamic, strong bodies and creative, active minds. People farmed and trapped animals with ingenuity. The earliest and most profound inventions—fire, the wheel, iron smelting, bridge building, fortification and agriculture—were a result of active minds and bodies alike. Tool development was—the fossils whisper to us—initially focused on warheads and crude knives. You can imagine that the tribe that killed the most efficiently acquired the homes, possessions, food and tools of the victims—winning genes conquered losing ones.
As humans developed the greater agility, speed and dexterity necessary to be successful hunters and warriors, they also evolved the ability to tame and exploit the land around them.
Two skills developed simultaneously: agriculture and hunting.11 Agriculture involved learning how to find edible fruits and vegetables, till the land, cultivate crops, harvest produce, and store and prepare it safely. All of this work was carried out manually, sometimes using animals. Hunting emerged as an efficient method for obtaining food and skins. Rudimentary tools became more complex. For example, spears tipped with flints soon became bows and arrows.
As the human brain evolved, more sophisticated strategies developed in both agriculture and hunting. Agriculturalists worked out which types of soil worked best for certain crops. Hunters developed strategies for killing animals with the greatest efficiency and safety; for example, massive fossil finds of animal bones demonstrate that early humans discovered that chasing bison over a cliff top was a simple way of gathering a great deal of meat and skin. All of this was done on foot.
Modern neuroscience has become intrigued by the idea that the brain evolved as human skills evolved. The brain is not a static mesh of electrical wires connecting one computer chip to another. Instead, there is abundant evidence that the human brain is constantly adapting to changes in stimuli.12 The brain changes both its structure and its function based on environmental cues. Over 2 million years of human history, the brain evolved in response to its environment and to the movement of the people within it.13
Advanced Brains, Advanced Psychology
The science of psychology thrived in Russia from the beginning of the twentieth century. For example, Lev Vygotsky, who died in 1934, led a school of psychology that developed the idea that higher cognitive functioning in children could be advanced through physical play, practical activities and the influence of an encouraging social environment. The communist regime then began to use psychology as one of its methods for sculpting an obedient society.14 Scientists took kittens (if you are a cat lover, skip the next few paragraphs) and reared them in dark boxes. After several weeks, they killed these kittens and examined their brains. They discovered that the visual cortex in the brain, which is the area associated with visual processing, had not developed. Later experiments with dark-reared kittens showed them to be blind at 15 to 20 weeks of age because the visual cortex cells were functionless.15 The part of the brain that would normally handle images had not developed because the cats were kept in dark boxes all of their lives until their miserable deaths. These early experiments demonstrated how environment influences brain structure. More recently it was discovered that there are brain chemicals, so-called neuroplasticity factors, that force changes in brain structure. These structural changes are subsequently associated with changes in brain function; this is how the brain adapts to changing environments.16
The human being evolved to walk millions of years ago, and over this time, the human capacity to think evolved too. The human brain is designed to think while moving, just as our bodies are. Knuckle-dusting apes left the forests of Africa and evolved to walk more and more upright; their brains would have adapted as well. Maybe then it is not surprising to learn that if this dynamic moving human was pushed into a chair, not only would the body suffer but so too would the mind. Sports cars are designed to be driven. If you take a Ferrari and allow it to sit idle for decades, it will clog with gunk. The human body and mind, though far more sophisticated, are equally prone to gunk up. Tie a human into a chair, and it seizes up and dies.
No Cats Were Harmed in the Writing of This Book
Talking about cats . . . When I lived in Cleveland, one Sunday afternoon I received a frantic phone call. “Jim, I need help,” my friend George said. “Come over,” he begged. He gave me an address; it was an apartment in midtown. George was sitting on a sofa with a half-dead cat on his lap. He was trying to feed her milk from a tea cup. She could hardly move. The apartment was in disarray. The cat had upturned and destroyed everything movable. The sofa had been shredded.
George had been asked by his girlfriend to look after her cat while she went on an archaeological dig just north of Addis Ababa. He received his first phone call from her three weeks later when she asked about the cat. He had completely forgotten. The cat survived, but George’s relationship with his girlfriend did not.
Ancel Keys, from the University of Minnesota, starved prisoners to examine the physiological effects of starvation. In 1944 he recruited 36 imprisoned conscientious objectors and then exposed them to 24 weeks of semistarvation.17 At first, with human starvation, Keys noted a short period of high anxiety with a twitching in subjects’ fingers and limbs. But then as starvation persisted, his subjects became more sedentary; they sat most of the day, and their spontaneous movements, gait and thought processing slowed. After six months of starvation, Keys observed his subjects during refeeding. The sitting stopped and the prisoners began to walk and think normally again.
The prisoners and the cat exhibited the classic starvation response. With starvation, there is an initial frenetic search for food. After a few days, though, the brain shuts down the body to conserve energy. Buffalo, lions, wolves, dogs, cats, rats and fish show the same behavior.18 In humans and Cleveland cats alike, movement, food and survival are inexorably linked. We move to eat to live. Movement defines life. Read on, because sitting is death.
How Evolved Are You?
How many of these activities have you done in the last week on your legs?
Scoring
Give yourself 1 point for each yes answer.
10+: Brilliant! Fully evolved!
8–10: Excellent. Evolving nicely, keep going!
4–7: Evolutionarily challenged. Much more evolution to do.
0–3: Dear oh dear! Homo sedentarius.
Humans have only sat for about 200 years, since we urbanized and industrialized. It’s obvious that as a species we are not designed for chairdom. And so the modern Homo sedentarius is idling, gunked up, stifled and sick. It is a common-sense argument, but where are the data? Is there science to confirm the evil of your chair?
When I first presented studies that sitting may be a critical trigger in obesity, one of the most senior scientists in the obesity field stood up in a packed scientific audience and screamed at me, “This is such garbage!” It amused me that he had to get out of his chair and stand in order to condemn the idea. At the time, my voice was alone. But over the last decade, evidence has grown faster than iPhone sales that sitting all day is lethal.19
Over the next few chapters, I’ll try to convince you that sitting causes an ABC of illnesses so haunting that you will start to despise your chair. Furthermore, I’ll uncover the depth of data that demonstrates how sedentariness connects to sluggish brain function and wandering thoughts—there is a reason you surf the Internet midafternoon: your mind has been rendered sluggish by your body.
The true cost of the sitting disease is even greater than the litany of medical illnesses. Most at stake is your sense of well-being. We all have a capacity for happiness. Sitting somehow suppresses it. Sitting is more dangerous than smoking, kills more people than HIV and is more treacherous than parachuting. We are sitting ourselves to death. How did no one notice?