When news broke that the CIA had used water-boarding as what it called an ‘enhanced interrogation’ technique, many around the world were rightly shocked. Simulated drowning sounds pretty terrible. Had the agency’s PR team been on the Machiavellian ball, it might have countered by playing up its other key methodology: sleep deprivation. After all, to keep someone awake for a while sounds considerably less dastardly. We’ve all had sleepless nights.
If only that was the case. Sleep deprivation has been used as a form of torture throughout history. During the witch hunts of 16th-century Scotland, getting confessions prior to conviction was crucial to what then passed for due process, and so ‘waking the witch’, as it was called, was invented. This involved depriving the poor woman of sleep for days at a time.
She was soon, within just 48 hours, experiencing hallucinations, instability, paranoia; within three days she was likely having waking dreams; within five or so days she had probably lost all orientation, and not just physically, but in time—unable to tell if the people in front of her were real or illusory, from the present or from her past. The ramblings resulting inevitably from these psychotic episodes were then handily interpreted as the law required.
Sleep deprivation was similarly used by the Japanese on prisoners of war during World War Two. It was used in apartheid South Africa during the 1960s and by the British against IRA suspects in the 1970s. “In the head of the interrogated prisoner, a haze begins to form. His spirit is wearied to death, his legs are unsteady and he has one sole desire: to sleep,” wrote the Israeli prime minister Menachem Begin of his own experience of being sleep-deprived by the KGB.
“Anyone who has experienced this desire knows that not even hunger and thirst are comparable with it. I came across prisoners who signed what they were ordered to sign only to get what the interrogator promised them. He did not promise them liberty; he did not promise them food to sate themselves. He promised them uninterrupted sleep.”
Remarkably, in 2004, the UK’s Channel 4 aired a reality TV programme called Shattered, in which contestants had to keep themselves awake for a week in the hope of winning GBP100,000. It was met with a storm of complaints. The Guinness Book of World Records has it that the record for the longest a human has gone without sleep is 11 days and 25 minutes, a feat achieved by one Randy Gardner in 1964.
He pulled himself out of what was a psychological experiment at Stanford University when, asked to repeatedly subtract seven down from 100, he got to 65 and then said he’d forgotten what he was meant to be doing.
Unsurprisingly, The Guinness Book of World Records no longer records attempts at sleep deprivation, lest it encourage people to risk permanent damage.
So why the gloom and doom, the talk of torture and hallucinations? Because, according to sleep scientists, many of us are wilfully subjecting ourselves to sleep deprivation—not of such a drastic form as outlined above, of course, but more a drip-feed reduction in sleep, consistently shaving off a couple of hours a night—getting five or six hours rather than the recommended seven or eight—over prolonged periods. And, they say, this is not a good idea.
“What effects can reduced sleep have over the longer term? Well, there’s the negative impact on mental health and emotional stability,” says Erla Bjornsdottir, a postdoctoral researcher in sleep at the University of Iceland and CEO of sleep health business Sleephubs.
“Then there’s the hormonal changes that come, which affect your appetite and lead you to crave quick energy, low nutrient foods, which come with weight gain. And then you’re so tired so you exercise less, which in turn enhances problems relating to stress, which in turn makes the subject more open to infection or depression… Really, health-wise, there’s not much not getting enough sleep doesn’t affect badly.”
The jury is out on whether we are getting a poorer quality of sleep now than we did in pre-modern times, and certainly there are a lot of misleading assumptions about how people slept in pre-industrial cultures. The idea that everyone slept a full night’s sound sleep before electric lighting and technology disrupted our ‘natural’ rhythms isn’t an accurate one: before the light bulb there were greater security concerns, for example.
Sleep habits have not been consistent through history either: prior to the 18th century it wasn’t uncommon to have two distinct periods of sleep over a night, with a spell of wakefulness in between during which a bit of candle-lit macramé or baby-making might occur.
But other studies suggest there has been a steady decline in hours slept over the last half century. An American Cancer Society survey of over one million people in 1960—and yes, lack of sleep might be connected to cancer too—found that just two percent reported getting less than six hours of sleep per night. Yet surveys in the 1980s suggested that percentage was climbing rapidly.
By 2004, a National Health Interview Survey in the US found that a whopping 30 percent of adults aged 30 to 64 were getting six or fewer hours of sleep each night. Put another way, sleep averages have declined by two hours over the last century at a pace that’s impossible for our brain to evolve in response to.
Indeed, while there are plenty of physical and psychological problems that exacerbate sleeplessness, in many instances we actively seek it. Analysis of a number of studies found—without proposing reasons—that you were more likely to be a short sleeper (as they termed anyone who got less than six hours) if you were a woman, single or divorced, had a college education, were African American and—most tellingly—were in full-time employment.
Human beings, it’s been noted, are the only species that will deliberately deprive itself of sleep, and it seems that work and our striving, go-getting attitudes to it are key in shaping our inaccurate perceptions of sleep health. Just ask any number of high achievers.
Jack Dorsey, the co-founder of Twitter, and Richard Branson, founder of the Virgin group, say they sleep only four to six hours a night; Indra Nooyi, who stepped down as CEO of PepsiCo in October, says she needs just four hours too; home-making entrepreneur Martha Stewart sleeps less than four, while, remarkably, designer Tom Ford has claimed that he only gets three hours a night.
Never mind companies; if you enjoy a long snooze, don’t run a country either. German Chancellor Angela Merkel and the UK’s Prime Minister Teresa May are both serious short sleepers. “In this job you don’t get much time to sleep,” May has noted.
And as for President Donald Trump, of course for him sleep is framed in the spirit of winners and losers. “How does somebody that’s sleeping 12 and 14 hours a day,” he has said, jumping wildly to the other end of the spectrum, “compete with someone that’s sleeping three or four?”
It’s not as though you can catch up later either. That weekend lie-in may feel restorative, but it’s not compensating for the health impact of short-sleeping the rest of the week. Evolution has yet to develop a mechanism that either compensates for lack of sleep or which can bank good sleep to offset a coming drought. Sleep is all or nothing.
“There’s this idea that getting by on less sleep is something to be proud of. There’s a macho quality to it. But it’s a disaster”
notes Dr Raphael Vallat, a research scientist specialising in sleep and dreaming at the Center for Human Sleep Science at the University of California.
“You tend to have all these CEOs and people in positions of power [declaring how they only need a few hours of sleep each night] which sets a terrible example and only perpetuates the idea. Interestingly it’s one that has particularly taken hold in the west and in the modern era. Go to Japan and even sleeping at your desk is considered a good step towards overall improved productivity. But in the west it’s as though to sleep is to be inefficient.
“The fact is that nobody can function as well on, say, four hours of sleep as they can on eight hours,” Vallat adds, emphatically. “It’s just not possible, not given the way the brain functions and not given the many ways in which sleep is absolutely essential to multiple brain and body functions. You might be able to do it for a week or two but in the longer term you’ll see some serious negative effects. And the problem is that most people suffering these effects don’t even realise it. It’s like being drunk. You think you’re okay.”
The changes towards a more sleepless society have been particularly marked over recent years. The rise of digital devices—and their use right up until bedtime, with all that brain-dazzling blue light—has been a great disruptor of sleep. Highly caffeinated drinks don’t help. And an always-on world—especially in big cities, but in a sense everywhere thanks to the Internet—has only exacerbated the problem further.
“In a 24/7 society we want to do more in a day because we can. So what many people tend to subtract from their day is sleep,” explains Professor Adrian Williams of the London Sleep Centre. “But, statistically, people who claim to get by on little sleep are just not aware of the impact it’s having on them. The question they should ask themselves is what amount of sleep they get when there’s no alarm clock involved.”
The last 30 years in particular have seen society adopt a standpoint that associates getting sufficient sleep with laziness: that ‘I’ll sleep when I’m dead’ mentality—ironically, given that lack of sleep is likely to get you to the exit door that much sooner. As Matthew Walker, the author of the best-selling book Why We Sleep, has noted, we don’t accuse a sleeping baby of laziness “because we realise that at that stage of life sleep is absolutely essential”.
Unfortunately, somewhere along the line we abandoned the notion that sleep is similarly essential through our lifetimes. He argues that we’re consequently facing a public health pandemic comparable to smoking 50 years ago. Part of the problem is that science is still in its infancy in terms of understanding why eight hours a night is essential. “The science of sleep is relatively new, though there’s more money going into studies of sleep now,” says Williams.
“Sleep has long been seen as a specialism too so the latest understanding of sleep isn’t getting down to general practice all that fast. Some 80 percent of sleep apnoea cases [a sleep disorder characterised by pauses in breathing during sleep] go undiagnosed, for example. And a quarter of middle-aged men have some sleep apnoea. So the importance of sleep is still largely under-appreciated.”
Certainly, in evolutionary terms, sleep seems like a dumb idea: while you’re sleeping you’re not gathering food, reproducing or interacting socially; you’re vulnerable to predators. And yet the fact that sleep is present in every species so far studied suggests just how essential it must be, in ways—given that the workings of the brain itself are barely grasped—not yet fully comprehended.
So far we know sleep is essential to the vital brain processes of repairing cellular damage, removing toxins that accumulate during the day and laying down memories. But much remains a mystery. Small wonder then that only a tiny sample of employers so far are making positive changes. Google and Nike, for example, have spaces in their offices where employees can sleep, while Proctor & Gamble has lighting that helps workers regulate their melatonin, the sleep hormone.
“I think the culture of skipping sleep is changing—slowly. We’re starting to see lots of successful people—the likes of Arianna Huffington [the Huffington Post founder, who became a born-again sleeper after collapsing from exhaustion] and [Apple CEO] Tim Cook say they sleep a good eight hours a night,” says Vallat. “People are using fitness trackers and apps to monitor their sleep too. And I think in the next 10 years or so we’ll see important changes in how people consider sleep.
“But first we really need better education, from school age onwards—not to scare people into getting more, because anxiety isn’t the best way of encouraging a good night’s sleep, but some kind of public health recommendations about sleep in the way there are now about nutrition,” he adds.
“Ask someone to choose between healthy and unhealthy foods and most people have a good idea. Ask people about the various stages of sleep, or what happens during sleep, and most people have no idea. And that’s amazing given that we spend a third of our lives asleep.”
Do we really need that much? Studies have suggested eight hours to be the optimum, though it’s also true that this oft-cited magic number is more a guideline than a hard rule. Confusingly, the health effects of getting too much sleep—more than 10 hours every night, or, if you’re Mariah Carey, reportedly 15 hours—can be just as marked as those of getting too little.
A solid seven hours is probably fine for most people assuming they wake refreshed most mornings, aren’t sleepy during the day, can concentrate on the tasks at hand and aren’t depressed—especially if you can also squeeze in an afternoon nap, another once commonplace behaviour that largely went out with industrialisation’s need for a regulated workforce hard at it for fixed hours.
In recent years there have been some claims as to certain people being genetically predisposed to needing less sleep. Like height or shoe size, there is a genetic component to individual sleep requirements—and it does seem that a genetic mutation, specifically that of a gene called Dec2, leads people to be natural short sleepers.
But most people who come forward claiming to have this mutation turn out to just be insomniacs. As for the tiny number of the others, perhaps they represent some X-Men-style future, humans already adapted to the pressures society has imposed on sleep over recent generations. As for everyone else…
Recently Vallat has been studying the effects of sleep deprivation in his laboratory. And the results have been disturbing. “What’s shocking for me is when I go back to the lab in the morning after a full night’s sleep and see how the test subjects look at me—their emotional state,” he says. “They can be aggressive, for example. And there are even moral ramifications—they’re more inclined to lie after losing sleep.
Really, we’ve got it round the wrong way in thinking we should get by on less sleep. We’re finding more and more issues. We’ve found, for instance, that people are less charismatic when they short sleep. They’re less inspiring. And that’s something CEOs and the others who claim to need only four hours a night might really like to consider.”