After weeks of bad sleep I’d had enough. Every morning I woke up tired and every evening I struggled to switch off my overactive brain, unable to drift off into a merciful unconsciousness. The problem was getting worse and starting to seriously impact my life. Something was wrong and I needed a solution.
Sleep, it is fair to say, dominates our lives. We spend roughly a third of our time in bed, and far more time feeling tired or sleepy. Bad sleep leads to under productive days and chronic poor sleep is linked to a shocking array of conditions, from obesity to depression. No wonder, then, that caffeine, the component of coffee that makes us feel more awake, is the world’s most popular drug.
For something that is such an important component of everyday life, we know surprisingly little about sleep. Despite millennia, literally, of research, we still have almost no idea why we actually do it at all. It probably, though scientists are not at all certain, has something to do with memory and with clearing accumulated chemical clutter from the brain.
Whatever the reasons behind it, we know sleep is important. Going without for more than a few dozen hours has serious consequences, starting with mental decline, passing through bizarre hallucinations and ending in death. Few people go without sleep for more than a day or two, but even a few nights of poor sleep, as I was experiencing, can have disastrous results.
The immediate impact is on memory and attention. For students and workers this is bad enough — college students who sleep less get poorer exam results — but for others the consequences are fatal. Every year more than a quarter of a million car accidents are caused by tired drivers, with the death toll in the thousands.
Getting better sleep, then, is not just a matter of feeling better and being more productive. It could, quite literally, save your life.
Our modern lifestyles have changed the way we sleep. Instead of the natural rhythms of day and night, electric lighting and alarm clocks now dictate our schedules. Instead of waking peacefully to sunlight and the sound of birds, we are jolted into consciousness by a blaring and unpleasant alarm.
As my quality of sleep started to decline, I began to wonder what was causing it. The more I thought about it, the more unnatural our modern style of sleep began to seem. Could this be the reason I, and so many others, were sleeping badly? I decided to find out, and hopefully along the way I’d find an answer to my nights of restlessness.
If modern life has caused us to sleep unnaturally, an obvious starting point was to ask how humans slept, and woke, before civilization started to mess things up. This, it turns out, was easier said than done.
Few things are known with certainty about human life before the dawn of civilization. This was, after all, a time of pre-history. Early humans left few traces behind. They had no writing, few ways of leaving traces and apparently gave little thought to communicating with the future. If we want to know, or at least guess, how they slept, we need to build a picture from scattered clues.
One approach is to look at our closest genetic cousins, the great apes. Like us, they sleep at night, settling down soon after dusk and waking around dawn. They build beds, something that sets them apart from monkeys, and often sleep with partners, much like humans do.
But they differ, at least from modern people, in how much they sleep, and how much they dream. We sleep less, even less than analysis of genetic relationships suggests we should. And we dream more, spending almost a quarter of our time asleep lost in dreams. These differences, scientists speculate, may have something to do with our bigger brains.
The great apes are not human, so care should be taken when comparing their behaviour to ours. But they can at least give us the contours of how we naturally sleep. We know from them that we shouldn’t sleep like cats, for example, napping frequently throughout the day, despite the claims of some rather more extreme sleepers.
Studying apes can only take us so far. To understand how our ancestors slept we need to turn to other techniques. Researchers have tried studying the few people who still live traditional hunter-gather lifestyles. These people, who live almost entirely outside the embrace of civilizations, maintain traditions stretching deep into our past.
Modern life has stripped us of the reference points of the natural world. Sunrise and sunset are no longer matters of life and death, and often pass us by unnoticed. The seasons fly by, the changing leaves and weather nothing more than an inconvenience. In air-conditioned homes we maintain a constant, comfortable temperature from January to July.
In the early days of our species these natural rhythms dictated our lives, but not quite in the way you might expect. We often think that humans slept when the sun went down, and woke up as it rose. But the researchers found a different story.
Hunter-gatherers may be on the fringes of civilization, but they are not entirely without technology. They have access to one important thing: fire. Fire doesn’t just bring warmth on a cold evening, it also gives light. And that means groups of people can stay up well after the sun goes down, cooking, working, or relaxing in company.
The hunter-gatherers studied by the researchers slept a few hours after sunset, long after any natural light had faded away. They awoke roughly around sunrise, but not exactly — waking a bit after in summer and a bit before in winter. These hours of sleep were not easily marked by light levels, instead the researchers found, temperature was a much stronger influence.
As temperatures started to fall in the hours after sunset, people started to sleep. In fact, the researchers found that sleep almost always started in this period of falling temperature. As temperatures started to rise again in the morning, people soon woke up. This pattern was strong and was repeated in tribes scattered around the world. It seems, in other words, to be a natural pattern of sleep.
What about other patterns we see in modern humans? Researchers have long known that people show a dip in alertness in the early afternoon, which sometimes manifests as a siesta or afternoon nap. Other studies, based on cultural records, suggest that people in the Middle Ages divided the night into two separate sleeps, with a period of activity in the middle.
The studies of hunter-gatherers showed no signs of these behaviours. They rarely woke up during the night — and actually seemed to sleep better than we do. There was scant evidence of them taking a siesta, except perhaps on very hot summer days, something that may again be linked to the temperature.
In many other ways their sleep was like our own. Contrary to popular belief, they didn’t sleep more than we do. In fact, they may actually sleep less, suggesting this problem is overstated in modern life. The seasons affected sleep, much as it still does, with people sleeping roughly an hour longer in winter than in summer.
The main differences, then, were the link to temperature, and the time we wake up. Nowadays we insulate ourselves in temperature controlled buildings, often maintaining a constant temperature throughout the day. When free of obligations, we wake up long after the sunrise, ignoring both natural daylight and the rising temperatures of dawn.
If I was sleeping badly, could the cause lie in one of these two factors? Could I sleep better if I adjusted my thermostat more intelligently? Could I somehow reintroduce the natural rhythms of our ancestors into modern life?
As it turns out, there is quite a lot of research showing that we can sleep better by mocking, in some way, those natural patterns. Take temperature. We often sleep in controlled environments, with little difference between night and day.
Our bodies have evolved to naturally cool as we prepare for sleep, but staying in a heated room counteracts that to some extent. Turning the temperature down before you sleep, or even just making your bedroom a bit cooler than other rooms, can help.
Another option is to take steps to cool your body before you sleep. A cold shower just before heading to bed can help you shed some heat, lulling you into a good night of sleep when your head hits the pillow.
What about the second natural rhythm we’ve lost, that of waking around sunrise? In the modern world it is hard to live by the sun alone. Today’s life is dictated by the ticking clock, not the natural cycle of day and night. We have to wake up to get to work, or take the kids to school, and we don’t often have the luxury of rising at the naturally optimum time.
Fortunately there is an alternative: sunrise alarm clocks. These clocks create an artificial sunrise in your bedroom, gradually brightening over a period of thirty minutes or so. The idea is to naturally bring you from deep sleep to a lighter sleep, so when the alarm does go off it is not a jarring attack.
Implementing these changes — lowering the temperature of my bedroom and body before sleeping, buying a sunrise alarm clock — did indeed seem to result in a positive change. It was not an instant change, but over a week or two my sleep noticeably improved.
With better sleep other areas of my life also got better. I was less tired, more focused, and better able to work on the things I wanted to do. The solutions to my sleep problems were not, in the end, that hard to find. Maybe I just needed a reminder that we are, still, products of our environment. Isolating ourselves from nature is never a good idea.
So much reporting around health, science and space exploration is unrealistic, hyperbolic and misleading. These are complicated topics, and there are often no easy or straight forward answers. Instead what is needed is analysis, discussion and an exploration of the possible ways forward.
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