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There is something of the English north-west in the Bay Area’s cement-coloured dome of a sky, and in Matthew Walker’s accent, too. The rest of him is purest California. A lateral sweep of blond hair suggests retired surfer or head stylist at a price-gouging salon. His actual job, professor of neuroscience and psychology at Berkeley, could be a heartland demagogue’s cliché of West Coast employment. Then there is the air of willing exile from someplace else. “I thought I would do a two-year post-doctorate position in America and solve the question of why we sleep,” he says, about his departure from Britain. “That was 18 years ago.”
We are either side of a corner table at Saul’s in Berkeley, the kind of teeming and unpretentious neighbourhood deli that might anchor a 1990s sitcom. On a very wipeable-looking harlequin-pattern floor, black-liveried staff tend to a multi-generational clientele drawn from local residential streets called things such as Cedar and Scenic. Even before Walker gets things going with a decaffeinated coffee, I intuit that this will not be a lunch that exhausts the wine list. I order a tamarind soda, whatever that is.
“People are stunned when I tell them the quarter-life of caffeine,” he says. “It’s 12 hours. So if you drink a coffee at noon, at midnight a quarter of that caffeine is still in your brain.”
“And what’s the zero life?” I wonder. “When does it leave your system?”
“Somewhere between 24 and 36 hours.”
Several years ago, in a quiet bar further down this strip, Walker, who had never written a book before, began to compose a manuscript about sleep and its health-giving properties. Thousands of words in, he sensed a woman at a nearby table peering over his shoulder as the text accumulated on his laptop screen. As she left, she leaned in and said: “When that comes out, I want to read it.”
“It was independent ratification from someone who had no reason to lie to me,” he says, sweetly discounting the possibility that a pick-up was in effect. “For the first time, I had affirmation.”
The resultant book, published in 2017, became a pop-science marvel, establishing its author as the world’s most famous expert on the physical act that takes up one-third of our lives. It also had the perverse effect of keeping some readers awake at night. Why We Sleep argues a causal link between sleep-deprivation and depression, heart disease, cancer and Alzheimer’s. Reading the book is akin to seeing a coin erode in a glass of Coke: it brings home the unhealthiness of a routine thing, in this case a restless night. The real terror of it is his definition of inadequate sleep: less than seven hours on a consistent basis. I am not sure I have cleared a regular seven since I outgrew the cot. “I have a non-negotiable eight-hour sleep opportunity window,” Walker says. He is lost to the world between 10.30pm and 6.30am.
I ask him if living on this side of the country helps. “Clichés are clichés because they’re true,” he confirms. “Despite the same work ethic that you would find in New York, what is different here is this notion of trying to maximise the self, quantify the self, hack the self. People are not embarrassed to say, ‘I can’t go out for drinks tonight because I’ve got to’ — what’s the phrase? — ‘kill my sleep score tonight’. So it spills over into a kind of health competition.”
At Saul’s, the menu (“No substitutions or modifications, please”) gives little quarter to the finicky, interrogative diners who are the bane of America’s waiting staff. I gamble on a turkey melt special. Walker asks for a mushroom omelette — egg whites only, the better to hack the self. “I don’t want disease or sickness in my life,” he says. There is a history of cardiovascular trouble in the Walker family. He pauses. “You do feel a little bit hokey sometimes,” he resumes, switching to the second-person pronoun, as people tend to when an insecurity has been activated.
In the 1970s, there was a fleeting literary genre known as Martian poetry. Writers would compose verse from the perspective of a visiting alien, describing human ways as if witnessed for the first time. In Craig Raine’s “A Martian Sends a Postcard Home”, books are “mechanical birds with many wings” that “cause the eyes to melt”. When a phone “cries”, humans “carry it to their lips and soothe it to sleep”. In the closing lines, he has a go at sleep: “At night, when all the colours die, they hide in pairs and read about themselves — in colour, with their eyelids shut.”
In the real world, we know how books and phones work. When it comes to sleep, we are not much less stumped than the Martian. Until the advent of brain-mapping technology, even academic scientists understood little about a nightly ritual whose prolonged absence would kill us. Walker, inquisitive from boyhood, began his obsession with the mysterious nocturnal when he realised as a doctoral student the scale of the ignorance about it.
Born in early-1970s Liverpool, he was a premature scientist. “My first experiment was when I was seven. I tried to falsify the existence of Father Christmas.” (Cheeringly, he “failed”.) At Nottingham University, he studied medicine but found it too settled a field to sate his curiosity. He converted to a then-nascent subject. “When I told friends I was switching to neuroscience,” he recalls, “they said ‘Don’t you need a language for that?’ They thought I had said Euro-science.” This was the early 1990s, before neuroscience and its findings transformed disciplines as remote as economics and philosophy, even bringing into question the idea of free will.
Then, during that epiphanic doctorate at the Medical Research Council in London, Walker noticed the dearth of knowledge about sleep. He also noticed a link between sleep and subtypes of dementia. He set up a laboratory with a grant to learn more. “I fell for sleep like a blind roofer,” he remembers. “I read everything I could get my hands on. I went to libraries to get old BBC documentaries on VHS.” His monomania, which he confesses was “asocial” at times, took him to Harvard and then to California. Now, on top of the Berkeley tenure and media appearances, he is a sleep consultant for companies as large as Google.
His passion goes beyond the onset of sleep to the strange, half-remembered movies that we watch in our slumber. Walker credits Freud as the first to attribute dreams to the workings of the brain, rather than to the soul, the moon, the spirits and other pre-modern mumbo jumbo. But he put forward no falsifiable hypotheses. “That is why science abandoned Freud,” he says. “He was also doing enough cocaine to kill a small horse when he was creating some of those theories.”
The turkey melt comes enfolded in a local sourdough with the discouraging name of Acme. It tastes better than it sounds, and, later, the carbohydrate crash turns out to be minimal. Whether in emulation or defiance of the craft beer movement, the Bay Area underwent a “bread revolution”, with a proliferation of artisan and hobbyist bakeries. Walker, as is the bane of the fluent dinner-table speaker, does not have a moment to enjoy his omelette. By way of respite, I tell him that, on the subject of insomnia, I can, as they say in these parts, relate. To meet his seven-hour minimum, I have to spend up to nine hours in bed, such is the slowness of sleep to come. But the wait is a pleasurable marination in free-associative thought that I would not do without. I theorise that, during this supposed dead-time, I process things that would otherwise nag me during the day or result in bad dreams.
“I would love to place some electrodes on your head,” he replies, as I contemplate a future as a medical curiosity, the toast of clipboard-toting sages from Berkeley to Bethesda. “A lot of people have sleep-state misperception. They think they are awake for longer than they are. My guess is that a lot of the cogitation that you are doing is actually happening during light stages of sleep.”
In conversation, he is a picture of control. There are no gesticulations, and few lapses into the upspeak that is the Briton-in-America’s quickest way of forfeiting his distinctiveness. In his even pitch he tells me that my benign experience of insomnia is atypical but not unheard-of. “You are one of the 10 or so people I have met in this long career who don’t take offence at the wakefulness,” he says. “Who almost embrace it.” It makes a difference that most of his case studies do not have a newspaper columnist’s, let us say, fluid schedule. The need to be in an office by a particular time can turn sleeplessness into a nightly ordeal for millions, hence the monstrous audience for his work. The wonder is that he never saw it coming. “I thought the book would die a death.”
Many readers will be able to guess the advice that he is about to give them. His value is in the Why, not the What. Consider, for instance, the folly of lying in bed waiting for sleep. “You wouldn’t sit at a dinner table waiting to get hungry,” he says, as our dishes are cleared, and I slurp the last of the soda. “The brain is such an associative device that it will very quickly build a connection between the bed and wakefulness. People tell me all the time, ‘Look, I’m watching telly, falling asleep, and then I get into bed and I’m wide-awake. I don’t know why.’ The bedroom has become a trigger for alertness. This is why insomniacs dread going in there.”
He also counsels against the junk sleep that is induced by sleeping pills. “You’re just knocking out your cortex,” he says. “Electro-physiologically, sedation is not sleep.” Nor, for all their ease of acquisition, are the pills harmless. “It was one of the few chapters where the publishers’ legal team took a lot of note. If you go up against Big Pharma, you print a crosshair on your back. But I stuck to the data. I didn’t make any claims that went above and beyond the science. I didn’t have to.
“If there is one piece of advice I would give everyone,” he continues, “it is regularity. If it is the weekend or a weekday, even if you’ve had a bad night of sleep, wake up at the same time.”
“And it’s not just wake up,” I check. “It’s get up?”
Damn. To quote the great John Cusack, I am not lazy, I just enjoy waking up gradually.
The closest thing to fatalism in Walker’s otherwise can-do world concerns human “chronotypes”. These, he says, are hard-wired. If you are a creature of the night, alert as a meerkat when most people are asleep, it is a matter of genetic wiring, not habit. You can hold to a “normal” schedule but will always be battling your nature. There is no reason to feel like a malingerer or a libertine for being at your best long after the working day.
Indeed, what chafes with him is the opposite stigma — that which dogs the prodigious sleeper. Vladimir Nabokov called sleep the “nightly betrayal of reason, humanity, genius”. Arnold Schwarzenegger advises those who want eight hours of the stuff to “sleep faster”. Margaret Thatcher was said to get by on just the four. It is this “sleep machismo” that Walker is set against, as well as the ambient glare of our “dark-deprived society”. As a contributor to good health, “sleep trumps everything”, and does not deserve its “image problem”. Insomniacs might try a “sleep divorce” (that is, separate beds from their partners). He has the phrasemaking knack of a speech-writer.
It is this blend of private scholarship and mass communication that qualifies Walker as a very modern figure. He is the latest iteration of a 21st-century trend. “Public intellectual” is the usual name for it but that suggests wide-ranging William Buckley-style rumination rather than academic specialism. Something about the P-word also implies a certain asceticism. “Entrepreneurial scientist” feels closer to the mark.
“I am by nature a very introverted person,” he says, as if anticipating this view, which is not meant as an objection. The waitress tops up his decaf as I ask for tea and the bill. “I feel very uncomfortable being in the public eye for the most part. But sleep is the neglected stepsister in the health conversation today and someone has to take that on.” He has, it is true, the particular social smoothness of the natural wallflower: always the slicker for having being worked on through trial and error. He also felt unconfident about writing for the public (needlessly: the book glides and amuses).
Purists in the academy resent such forays into the mass market, where doubt and nuance can go missing. Why We Sleep is very sure of its argument. But amid the west’s supposed turn against expertise, there is some cheer to be found in the public’s ravenousness for specialised knowledge. It has elevated the rationalist likes of Walker (and Sam Harris and Steven Pinker) just as frontline politics brims with out-and-proud ignoramuses.
And how telling that while these popular intellectuals vary in their emphases, they often converge on the operations of the brain. Generations ago, the public boned up on history (through AJP Taylor) or art (through Robert Hughes). Today it is scientific knowledge of the self that is the admission price to polite company. We are all Californians now.
Walker drains his coffee to a frothy web and tells me that he will “work with any first-world government that wants to build a public health programme around sleep”. We step out into a Merseyside-ish day. “I have a Herculean task of public advocacy ahead of me,” he says, taking his leave, eight hours and 39 minutes before bed-time.
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