But I’m Not Sleepy!

Here’s the second Psychology Today blog post:

One of my strongest memories from high school is the feeling of that extra hour of sleep when we fall back into standard time each autumn. After the first few weeks of school, and the mounting sleep debt of having to wake up at too early of an hour, having that extra hour of sleep felt exquisite. But the eventual transition back to Daylight Saving Time in the spring was excruciating. Losing that hour of sleep made school much more difficult – at least until my urge to sleep aligned with Daylight Saving Time. My circadian rhythm was generally not the same as the one that I needed to get through the school day without feeling sleepy. This situation made very apparent to me that it’s arbitrary when we start school and work, and that my need for sleep was often at odds with those decisions.

Our circadian rhythms are the result of complex interactions between our body and our environment, and are generally seen as the force that cues us to feel sleepy. On one side, we have the urge to be awake. On the other, the need to sleep. When one overtakes the other, sleep or wakefulness ensues. As we sleep, the need to sleep reduces, and our alerting functions take over – until the need for sleep builds up again and we head for bed. Scientists have suggested that circadian rhythms govern much more than our need for sleep, including our urge to defecate and our appetites. We can delay our need for sleep – or eating or defecating – temporarily, but we can’t defer it indefinitely.

In his book, The Promise of Sleep, William Dement recounts the case of Randy Gardner who stayed awake for eleven days – but we now know that anyone who stays up for too long starts to microsleep as their need for sleep forces them to rest, even while their eyes might be open. As much as we might fight it, our circadian rhythm shapes our sleep.

Many people would tell you that our circadian rhythms are innately tied to the environments we’ve evolved in, but that’s not strictly true. Over the millennia that humans have evolved, they’ve inhabited a number of diverse environments around the globe, all with their own light cues – in circumpolar regions, humans have lived in periods of prolonged night and day; in equatorial regions, humans have been exposed to roughly equal periods of night and day. Sleep, in both of these environments – and all of the environments in-between – has developed as both a social and biological response to these cues. We sleep when we’re tired, but we also tend to take to our beds when the nights are long and we have limited light and heat. This has resulted in a wide variety of sleeping schedules – from societies that favor a midday nap to those that favor a long night in bed. And, then there’s the United States, that tends to favor a short night in bed – eight hours or less – and no midday nap, except for the very young and the very old.

If you were to measure the circadian rhythms of people throughout the world, you should find that there are a wide variety of expressions of circadian cues. But when we look at the science of sleep, one representation of circadian rhythms prevails, and it often looks like this – which I’ve borrowed from Dement’s Promise of Sleep, and which I talk about extensively in my book, The Slumbering Masses:

This model is based on individuals sleeping for eight hours at night – from 10 p.m. until 6 a.m. But what if that individual took a nap in the middle of the day? Her sleep need would decrease accordingly and start to rise again. At bedtime, her sleep need would be less, but still enough to get to sleep. Or, if she slept in two four-hour blocks throughout the day, the need would be more balanced, and never so great that her urge overtakes her need – she wouldn’t just spontaneously fall asleep while in a meeting or driving home.

If we consistently slept in different patterns, our circadian rhythms would look quite different – both because of how we slept, but also because of other environmental cues, like food and light. Humans have evolved to have flexible circadian rhythms, and beyond just patterning of sleep shaping our rhythms, our exposure to light and our consumption of food shape our urges for sleep. This is one of the keys to understanding jetlag: when we go from one set of environmental cues to another, our bodies often react negatively, with our cues for sleep being mismatched to environmental cues. Only after we adjust to the new patterning of light and food intake do we begin to adjust to the new time zone, and our sleep follows suit. This can take a while, in part because our adjustment to food intake can be rather slow, whereas light impacts us quite quickly. Adjusting to Daylight Saving Time is often no big deal, because it’s a slight variance in time and we adjust our schedules accordingly. But adjusting to a bigger time difference – a few hours or more – can often leave us with a serve sense of being dislocated in time.

Despite the relative flexibility and variation of circadian rhythms, the models we have of our biological cues are fairly rigid and are based on the assumption of nightly consolidated sleep and large meals throughout the day. If we slept in two four-hour blocks, or one nightly block supplemented with a daily nap, our rhythms would alter. If we ate smaller meals throughout the day as well, our rhythms would again look less dramatic in their highs and lows. But such an organization of sleep and eating would depend on us investing in a much different ordering of society. The result would both be a dramatically different experience of sleep for us – as individuals and as members of society. And it would change how we conceive of normal and pathological sleep. What we now think of as sleep disorders – narcolepsy, insomnia, shift work sleep disorder – might not be so pernicious and in need of medical treatment.

But changing society to ease our discomforts around sleep seems unlikely – if it’s ever going to happen, it’s going to depend on denaturalizing our conceptions of human circadian rhythms and to take seriously how other orderings or society might benefit our biological experiences of ourselves and the world.

How Natural is Human Sleep?

Here’s the first of the blog entries for Psychology Today:

You’re sitting at your desk, slowly reading through your response to a friend’s email, when you feel the sudden tug of sleepiness. The next thing you know, you’re waking up with your head on the desk, your hands folded under you in a makeshift pillow. Or, your riding on the train, playing a game on your iPhone, when the next thing you know you’re waking up and reaching under your seat to fish for your phone. You haven’t been napping long, so hopefully nobody noticed. Maybe it’s just incidental sleepiness – you haven’t been sleeping well lately – but it happens with more and more regularity. Maybe it’s time to see a doctor about it?

Over the last decade or so, Americans have become more and more aware of sleep and its disorders. One way to think about this change in public awareness is that it’s due to the new recognition of sleep disorders – that science has discovered new pathologies, their causes and cures. This might appear to be the case with narcolepsy, the sudden onset of sleep, often associated with momentary heightened emotions, which has been diagnosed more commonly since the 1970s. In fact, we’ve had a reasonably well-articulated sense of narcolepsy since the 1820s, thanks to Scottish physician Robert Macnish, who described it as ‘drowsiness’ in his Philosophy of Sleep. We still don’t really know what causes narcolepsy, but we do have treatments for it that are reasonably well tolerated by narcoleptics. And this might be the reason why we’re paying so much more attention to sleep these days: changes in pharmaceuticals. But that’s not strictly true either, since throughout history we’ve have suitable if not wholly effective treatments for a number of sleep disorders – we just prefer pharmaceuticals to changes in lifestyle these days. Rather, our heightened interest in sleep has everything to do with our disconnection from history and the many changes that American sleep and society have gone through over the last two centuries, which make a lot of phenomena seem new, when we’ve been living with them for centuries.

About a year ago, I was on a conference panel with a laboratory scientist who specializes in developing technology for the assessment of sleep disorders; he gave a presentation on the state of the art in sleep science and medicine, a talk designed for his audience, which was largely comprised of scholars in the humanities and social sciences. Meanwhile, I gave a presentation focused on a minor event in the history of sleep science, an experiment led by Nathaniel Kleitman — then a professor of physiology at the University of Chicago — aboard a U.S. Navy submarine to ascertain the ideal arrangement of sleep while at sea – which I discuss in my book, The Slumbering Masses: Sleep, Medicine & Modern American Life. During the question and answer period, an audience member asked my co-panelist about changes in scientific conceptions of sleep, to which he answered – and I’m paraphrasing here – ‘That’s not my job, it’s yours.’

I’ve heard similar sentiments from scientists and physicians before – they’re busy on the frontline, dealing with the demands of patients, writing grants, and conducting their own research, and don’t have the time to do investigative social research. At one conference where I was talking about the history of the sleepwalking defense for murder cases in the U.S., I saw more audience members – scientists, physicians and other medical professionals – take more notes on my quick discussion of the history of narcolepsy than on the changing conceptions of intent in American law, both of which, I was attempting to convince my audience, you can’t fully appreciate without understanding the U.S. in the 19th century.

Although social scientists are sometimes seen as lobbying groundless critiques at laboratory scientists, one of the things that social scientists are especially good at is debunking things that we’ve come to accept as natural. This process is often referred to as denaturalization – showing how what we take to be natural is the result of a history of human action that has moved something from being understood as social to natural. One of the cases I discuss at length in my book is that of consolidated sleep in the U. S. The eight hours of sleep so many of us seek out each night is not based in nature, but instead is the invention of many doctors, scientists, and business owners, and began in the 19th century to only be fully realized in the 20th.

Previous to the mid-1800s, many Americans slept in what’s referred to as biphasic fashion. That is, they would fall asleep around dusk, wake up a few hours later for a couple hours, and then sleep for a few more hours before waking around sunrise. Or, they would sleep for a few hours at night and a few more during the day. We have evidence of this in England, thanks to historian Roger Ekirch, and, as I discuss in The Slumbering Masses, American medical literature in the 19th century is full of references to these kinds of sleep patterns. When you think about it, our nights are often much longer than eight hours, so even if our sleep is determined by our environments, we would assume that humans would sleep much more than they do; instead, humans need less than a full night’s sleep as reckoned by the sun. We need somewhere between 6-10 hours each night, a figure that changes over the life course, with children and adolescents needing more and the elderly needing less. How we manage to get that sleep is up to us, or, rather, it’s often up to social norms.

In the U.S., we tend to prefer nightly, consolidated sleep – eight straight hours, with no nap during the day. For preschoolers it might be different, with longer nightly sleep and naps to boot. But, elsewhere and over the course of history, sleep arrangements have been different. In their efforts to understand biological phenomena, scientists can sometimes substitute what they believe for scientifically deduced fact. This is the case with American models of sleep, where early researchers in the 20th century used the consolidated model of nightly sleep for the basis of their scientific research (which I discuss in Chapter 2 of The Slumbering Masses). If they had used different models – say models that favor biphasic sleep – contemporary sleep science and medicine might look a lot different than they currently do.

Social scientists then, and cultural anthropologists especially, work hard to denature the facts that have come to be taken for granted – by scientists and the public. Critique of this sort is important for a number of reasons. First, it serves as a corrective when beliefs come to be taken as facts. Secondly, it opens up science to be a dialogue. When science is only happening in labs, it’s liable to be susceptible to the biases of researchers and the expediencies of grants, publication and promotion – hence the recent increased awareness about the prevalence of fraud in scientific publishing. And, most importantly, it infuses science with the lived experiences of individuals – which is why we do science in the first place: to make our individual and collective lives better. So when we take scientific fact as the basis of our lives – whether it be something we read on the internet or a pill we’re prescribed – we should always consider whether it helps us make sense of our life. And if it doesn’t, we should keep looking for answers. Some of those answers might be found in history or in other societies, where we might come to see that our sleep hasn’t always been what it is or that we might arrange our days and nights differently. This isn’t so much debunking science as helping bring it to life.

School start times: Why so rigid?

Here’s the latest from the UMN Press blog, on school start times:

Over the past thirty years, there’s been a mounting body of evidence regarding changes in long-term sleep needs. Infants need a lot of sleep; children less so; adolescents need more; and adults, less, until our later years, when many require even less sleep.

So over the life course, it’s perfectly normal to sleep as much as twelve hours (even more for infants) and as little as four in a day. Along with these changes in sleep needs are changes in the time of sleep onset: as infants, most of us fall asleep earlier than we will as teenagers or adults; in our later years, we’ll wake up well before we do as children or adults. Sometimes we think about these differences in our sleep as pathological and seek out medical help, especially adults who start sleeping less than they used to, who often complain of insomnia despite feeling well rested.

But before we’re adults, we’re often at the mercy of other people’s interpretations of our sleep. And no one has a harder time garnering respect for their sleep needs than teenagers.

As a teenager, I started high school at 7:30 a.m. (yep, Rochester Adams still hasn’t changed its start time since then.) I would often get to sleep around 11 p.m. or later – not because I was playing video games or texting, which didn’t exist in 1991, but because my circadian cue for sleep onset was later than it had been when I was a child. I would have to wake up around 6:30 a.m. to be to school on time, which often meant that I was sleeping 6 or fewer hours each night. I don’t think I remember anything from my first two periods throughout high school. I would sleepwalk through my morning and “wake up” around midday. I would often nap in the afternoon. And still my daily sleep wouldn’t add up to nine or more hours.

There’s a nice piece on the CBC about experiments with changing school start times that includes an interview with the principal of the Canadian schools involved. It reviews the science of adolescent sleep, which shows that sleep onset at adolescence is later – sometimes as late as 11 p.m. or midnight. Alongside that later onset is a need for greater sleep, on average ten hours each night. The school day for students participating in this program runs from 10 a.m. until 4 p.m., no shorter than for those peers who start at 8 a.m. or earlier. And there’s some anecdotal evidence that it improves grades and attendance. What’s most interesting about the story – as is so often the case – is the comments. Adults weighing in on this change in start times refer to teenagers as lazy, point to their distraction by media technologies and lack of daily labor, and generally dismiss the science of sleep.

Was I just lazy as a teenager?
Are today’s teenagers more easily distracted away from sleep with the proliferation of media technologies?

The science says no. But why might adults be so rigid in their thinking about the social obligation of the school day? Many commenters on the CBC article fall into a slippery slope fallacy, assuming that today’s “lazy” teenagers will be tomorrow’s “lazy” workers and demand that work times shift to later in the day as well. The science doesn’t point to the need to change our work days – though there have been some movements towards flextime and workplace napping – but many of the adult commenters don’t even appear to buy the premise that sleep needs change throughout the life course.

As I discuss at length in The Slumbering Masses, the basis of modern school start times lies in the 19th century, when public schools were developed to care for the children of day laborers—meanwhile, the elite would send their children to boarding schools. The school day developed alongside the industrial workday to allow parents to drop off their children while they worked. There’s nothing natural about it—it isn’t based on some agrarian past where we were more in balance with nature. Instead, it had everything to do with the need to fill factories with able-bodied adults from dawn until dusk and to keep their children busy. Only slowly did this change, as American work schedules changed. Now science can support the organization of our daily obligations – or at least support the advocacy for more flexible institutions, that take things like variations in sleep need seriously.

But why be so rigid in thinking about teenagers being lazy and school start times being just fine as they are?

One of the things that comes through in the comments to the CBC story is that many adults feel as if they did just fine in high school, and that today’s youth should be just fine as well. In one commenter’s language, changing school start times amounts to “molly coddling” teenagers and playing into their entitlement. High school, it seems, is hazing for entry into the “real” world of adulthood, emblematized by work. While this is surely part of what school is intended to do – it models the demands of the workday with deadlines and expectations of outcomes – it is primarily intended to produce competent citizens. If changing the start time to slightly later in the day leads to more engaged citizens and more capable workers, shouldn’t we change our school days?

More insidious and less obvious is that many people have come to think of our social arrangements of time as being based in some innate human nature. If we accept the basic premise that sleep changes over the life course, that alone would nullify any standard of time usage. But many people tend to rely on small sample sizes to think about what’s natural and what’s not; just because modern social formations work for you – or seem to – doesn’t mean that they’re natural or that they work for everyone. How many cups of coffee do you drink each day? Or how much caffeinated soda? Have you eaten a snack today to offset sleepiness? Or taken a nap? Could you have gotten through your day a little easier if you slept in an extra hour?

There’s nothing natural about alarm clocks. And many sleep researchers and physicians would say that they’re one of the worst things for good sleep. But we use them anyway. Maybe it’s time we start to take the science of sleep a little more seriously and begin to rethink how we want our days to be organized. If we could be happier and healthier workers and students, it’s worth the investment in change and thinking past our expectations of nature and norms.