The Cultural Aspects of Sleep
What constitutes a good night sleep? Here in the UK, we're told that it's a solid 8 hours overnight, tucked up in bed in the dark and in the quiet. But if we don't do that or if we can't do that, we're thought of as being unusual or we're told that we have a sleep problem. Helen Ball, Professor of Anthropology at Durham University is looking into the cultural aspects of sleep...
Helen - We're interested in the mismatch that happens between our evolved physiology of sleep and the way in which we sleep in modern Western societies. So we're looking at things that we think of as sleep problems in our society but that when you look at sleep habits across the world, they're actually normal human sleep patterns.
Ben - We are fairly well conditioned to think that we need to go to bed at a reasonable time, get 8 hours solid sleep in one block, and this obviously fits around work or school, or our lifestyle. Is that backed up by good science? Is that physiologically a healthy way to sleep?
Helen - Well that's how sleep has been studied in sleep laboratories because that's the model of what good sleep is in the Western world but if you look at historical reports, there's an interesting book by a guy called Roger Ekirch called "At Day's Close" and he looked at a lot of diaries from between 5 and 200 years ago and he found people talking about how they would have a first and second sleep. So you would go to bed at twilight, you would spend a couple of hours relaxing and winding down. You'd sleep for 4 or 5 hours then you'd wake up and you'd have what was called a "watching period" where you're quiet awake for a couple of hours, and then you'll go back to sleep for another 2 or 3 hours.
It puts me in mind that some of the problems that people think that that we have with insomnia and the insomnia epidemic that we supposedly have in the Western world is actually an artificial creation of trying to force ourselves to sleep for a solid block when actually, physiologically, that's not what our bodies expect us to do.
Another issue is trouble falling asleep in the evening, and there's a lot of sleep hygiene advice out there about what you should do if you're having trouble falling asleep. Some of it makes a lot of physiological sense like staying away from things that act as artificial stimulants like computer screens and TV screens, and obviously, caffeine and stimulant drinks and all the rest of it. There are other things about sleep hygiene that are really just culturally conditioned, but if you think about how people would have slept throughout history and do sleep around the world, they don't sleep in soft, comfortable beds, and they don't sleep alone in silent conditions, et cetera. And so, we've entrained ourselves to expect this very rigid and constrained sleep environment.
In some respects, we're setting ourselves up to have these sleep problems and one of the things that I've studied the most is the sleep of infants and the way in which we expect infants to sleep. Parents start out by trying to teach their infants to sleep for long periods of time in dark, quiet rooms, and they tiptoe around them so they don't wake them up, but babies all around the world sleep in hugely social, noisy environments, being carried around, et cetera, so babies can do that. There's no reason our babies can't do that. We don't have to teach them that the only way to sleep is in a silent room with the lights out, with a very comfortable warm bed.
Ben - It's also true that the amount that we sleep, the amount we need to sleep and the times that we need to sleep change quite dramatically through our life.
Helen - Yeah, this is another good point. Historically, over the last 50 or 60 years, we've tried to get children to do what we call "settling" which is starting to consolidate their sleep into night time chunks earlier and earlier, and earlier. People now are trying to sleep train 3-month old babies and 3-month old babies physiologically aren't ready to have their circadian rhythms entrained in that way.
Children do need a much greater amount of sleep than adults do but if you do a survey of how much children sleep, it ranges anywhere from 9 hours to 15 hours. So, there are biological differences in people in terms of how much sleep they need, but then there are also differences in the ways in which the amount of sleep your body needs can be obtained in a 24-hour period. One of the things that we found in interviews with parents is that they're very resistant to the idea of children having naps during the day in UK culture because [they worry that] if children have naps during the day, they'll stay awake at night. But if we look again at other societies and even the US, there's a very familiar culture there in kindergarten of children having naps in the middle of the afternoon.
Ben - And just lastly, do you think we should try and change our society to fit our sleep needs? Should we have no early morning lessons for teenagers and the ability to have flexi-time at work in order to suit our own sleep patterns?
Helen - Well, the idea of later starts in the morning for teenagers, it's a very popular one. It's been done in some schools in the States and it does seem to have made a difference to academic performance. There is some evidence that teenagers' sleep patterns do undergo a shift, so that they do biologically go to sleep later and wake later so it makes sense to do that. But yes, I think the idea of people being able to incorporate their work lives around their sleep needs is a very good one so more flexi-time would be an excellent idea.