In this episode: We all know that your sleep influences your health. But how you sleep is influenced by factors beyond the decisions you make about bedtime, staring at your phone, and drinking coffee. In part II of our doubleheader on sleep science, we ask about the “social determinants of sleep health”—all those ways we organize our world that affect our sleep and hence our health. In chapter one, demographer Lauren Hale (8:11) explains what sleep-related factors most influence health, and what makes a disparity into an injustice. In chapter two (18:20) we return to Michael Grandner’s interview for some insights into how racism shapes sleep and influences how he talks with patients in the clinic. Roxanne Prichard (33:10) reminds us that sleep is a feminist issue, and that teens are unlikely to get up early. Lauren (43:32) chimes in on the evils of phones and school start times.
Mentioned in this episode: Lauren Hale’s profile; Michael Grandner’s profile; Roxanne Prichard’s profile; outro is comedian Pete Holmes. Thumbnail credit: Viktoria Hall-Waldhauser (viktorialuise, CC0) via Wikimedia Commons.
Transcript:
Cressida: 00:00
Joshua didn't want me to say this, but I asked I asked AI, I got desperate. We don't use AI for the podcast except for except for transcripts.
Joshua: 00:09
Except for this explicit time.
Cressida: 00:10
But I deviated and I asked AI for a tagline suggestion and I got for this episode. We're told that a good night's sleep is a matter of personal discipline. Better blackout curtains, less caffeine, and a strict bedtime. But for millions, sleep isn't a choice. It's a luxury determined by their postal code, their paycheck, and the noise outside their window.
Joshua: 00:33
It's almost worth running a river dry. Almost worth emptying a lake for that.
Cressida: 00:38
That's it gave me answers in a different tone, and that's provocative tone. I'm like, oh honey, you ain't seen provocative.
Joshua: 00:46
Oh, that's very tame.
Cressida: 01:16
And in episode one, we talked about the idea that there is a sleep crisis. I think we can see from some of our guests' comments last time that whatever that crisis might be, it's emerged from the ways we organize our societies around waking rather than sleep.
Joshua: 01:32
Right, we started talking about how biology and culture might not always be aligned.
Cressida: 01:40
Yeah, and so our question then is where are these misalignments felt especially keenly? And the answers from our guests seem to be that even if there is a general problem with sleep, there are also some groups of people who are struggling with sleep for particular reasons.
Joshua: 01:55
Yeah, and so one of the expressions that we're going to hear come up a lot is the social determinants of sleep health. Can you explain what that means?
Cressida: 02:06
Yeah, sure. So the usual list of social determinants of health, you see this phrase everywhere in a certain genre of medical research, includes things like income, employment status, educational level, ethnicity, living conditions, and so on. So these are distinguished from medical causes of disease, like genetic mutation, high lipid levels, viral infection, or whatever, but rather aspects of who we are and how we live that shape our health in ways that we have organized, so social determinants. And these factors mostly correlate with health outcomes on what's called a gradient. So the higher your income, the better your health, for example, generally speaking. The more education you have, the better your health, and so on. Just speaking statistically, where there's obviously individual exceptions. So of course, the problem here is that social determinants of health are wrapped up with medical causes. So if you live in overcrowded conditions, you're more likely to pick up viral infections, as we learned during the COVID pandemic.
Joshua: 03:15
I remember that. You remember?
Cressida: 03:17
Yeah. But it would be good to improve the quality of housing and increase basic income so that nobody had to do so. Right? If you eliminate overcrowding, you reduce viral transmission rates, right? Basic stuff. The implication of identifying the social determinants of health is that we could social differently.
Joshua: 03:36
A wonderful phrase.
Cressida: 03:37
I said that. And this isn't exactly or not always the business of healthcare professionals, so much as other kinds of interveners, like social workers, political activists, or public servants making policy.
Joshua: 03:50
Okay, so I think I can start to tease out how this would relate to sleep, but why don't you why don't you tell us?
Cressida: 03:59
Okay. So social determinants influence sleep. And we know that how you sleep is a key determinant of health outcomes. So one of the challenges here is to work out what the causal pathways are, what is causing what in this big picture. So if there's a sleep crisis, such that we want to improve sleep, we could try and change some larger practices rather than only trying to change individual behavior. So those pesky sleep tips are not the only game in town.
Joshua: 04:34
And okay, I could see where that's that would be generally true, but I can also see two different pitfalls here. The first is how do we know which social differences are unfair? Educational attainment is not only a matter of social privilege, although it has a lot to do with that. It's also to do with various talents and abilities that people have. Now everyone can or should go to university. So differences in available educational pathways seem legitimate. I'm not sure how to reconcile that with the knowledge that people with lower levels of education have worse health.
Cressida: 05:10
Yeah, it's a good point. And I think it shows that we have to disaggregate causal connections here. Like, is the reason that people with better education typically have better health the fact that they understand how to be pushy in hard-pressed, resource-poor public health care systems where they might be more likely to class identify with a doctor or someone else who's talking to them about their health? Is it that they're better placed to understand instructions that are given to them about things that they should be doing or pills they should be taking? Is it prejudice against people with lower levels of education on the part of healthcare providers? So there's lots of different sorts of things that would influence why education generates stronger health outcomes. And some of them we might want to mitigate because of social justice reasons, like don't be so prejudiced against your patients who who don't have so much education. And other parts of it might just remain kind of artifactual.
Joshua: 06:19
Right. Okay. That makes sense. The the other pitfall is that people will just choose to do things that are bad for their health. And short of, you know, monitoring, hyper monitoring, and over-governing. I'm not sure how we social engineer around that.
Cressida: 06:38
Yeah. And that's a that's a thing you hear a lot. And of course, it seems like something in some respects we might have to leave alone. People choose to eat junk food. Popular example. I sometimes do. And I'd like to see the government try and stop me, because I'm a true Albert no, I'm not really. But, you know, concerns about the nanny state creep in when we're trying to manoeuvre people into better health behaviors, but that's different. So saying, you know, the government shouldn't try and stop me from eating junk food, I don't even know if I believe that actually, but that's different from living in a food desert where the only things I can buy are junk. So if that's my environment, I really don't have any kind of meaningful choice. So figuring out which social determinants of sleep health are unjust and what it would mean to create a world in which people had real choices, even if they didn't always choose what their doctor would like, seems like a way of improving population health, including sleep health.
Joshua: 07:43
Right. So to begin tackling these sort of questions, we are gonna go to our guest, Lauren Hale, who is a demographer, someone who analyzes these trends across populations, and she looks at the big statistical pictures of social differences, sleep differences, and health differences, and tries to work out what's causing what.
Lauren: 08:24
My name is Lauren Hale. I am a Professor in the Program for Public Health in the School of Medicine at Stony Brook University, which is in Long Island, New York. And for about 20-some years, I have been studying the social patterning of sleep.
Cressida: 08:30
What we're trying to do in this episode is to move away a little bit from our emphasis on the cultural politics of sleep. So if you listen to season one, there's lots of episodes about art and literature and law and so on. But people keep asking Joshua and I for advice about sleep. And we look sort of awkward or uncomfortable or embarrassed and say, we don't really do that, and we should, we're not doctors, and we shouldn't really give you advice about sleep. But there is a kind of really powerful desire, I think, in the audiences that we connect with to get good health information about sleep on an individual level. And what we wanted to do with the episode was not exactly to scratch that itch, but to show people that there are ways of thinking about sleep that are to do with the health sciences, that are not just being given helpful tips about how to make your bedroom cool and dark. That there's a science here that extends beyond that kind of facile advice giving. And to look at this bi-directional relationship between culture and individuals. And everybody we've talked to is clear that there is that relationship. Like nobody thinks that sleep is just a biological phenomenon any more than people on the social sciences side think that sleep is purely cultural, right? Everybody agrees that all of these things are mutually interrelated. So when you just say that your work addresses the social determinants of health, maybe let's start there. What does that phrase mean?
Lauren: 10:05
The phrase comes from the field of social epidemiology to refer to non-medical conditions of life, social, economic factors, employment, housing, all these things that affect health. And that's the social determinants of health. And then I take it a little bit further and say all those things also affect sleep, and in the same way, you know, almost almost to a T. Like you could just substitute the word health with sleep, and you're like, oh, they're all the same. But since nobody had really studied that before, that was the little tweak that I did or have been doing, still doing it.
Cressida: 10:49
Yeah, so so of that litany really of social determinants, um what are the biggest relationships that you see between whatever it is and sleep? Like what's the big picture here?
Lauren: 11:05
Right. If you're talking about magnitude, the things that matter most for sleep is things like work schedule, school start time, things that affect timing, massively important. But some of those you choose those, or you at least choose whether you want to work a night shift or not. But if you're thinking about equity or fairness, I'm particularly concerned about racial differences in sleep, where we do see very big differences, up to an hour difference per night between black men in the US and white men. I mean, that's a really huge difference. It's cumulative. We see differences by education, not so much by income, sort of surprisingly, neighborhood factors. But you know, some of those are more or less modifiable. So we want to I want to get to the things that we can do structurally to reduce uh these, I would just call them unfair differences or unfair disparities in sleep.
Cressida: 12:20
So Lauren gives us a big picture about how her demographic research sees the social determinants of sleep health. And she mentions that the largest influences on sleep health are anything that affects how much control you have over time, which I think is a good way of showing the big picture here. You know, like having control over your time is so consequential. So shift work, for example. She also mentions racial differences, education, and neighborhood.
Joshua: 12:49
And she is very interested in what makes a disparity in sleep that causes negative health outcomes into an injustice, and in turn, which of these are modifiable. I guess because in public health, you can be interested both in identifying causal explanations and in designing policy responses.
Cressida: 13:08
Yeah, I mean it's all very well to say that you know X is causing Y, but if you can't really do very much about X, it's not so exciting. Whereas if there's a possibility that it's tractable, then you're you get more motivated. As we'll see in a later episode on precarious housing and sleep, in some areas the challenges facing policymakers who want to improve any aspect of population health, including sleep, can be enormous. How the housing stuff is really I mean, there are just so many huge problems. And as we said off the top, there's an important equivocation that reappears here and throughout Lauren's interview, actually, about how behaviors that are chosen or voluntary shouldn't be understood as unjust. Would you agree with that, Joshua? Putting you on the spot.
Joshua: 14:00
Yeah, I so in political theory, we would want to identify like structural causes of injustices and then individual responsibilities for injustices. And typically those map into different political projects too, right? If you want to blame the structure, you are typically hoping to improve that structure or modify that structure in a more just way. And this might just be my bias in the way I explain these, but if you are preferring to blame the individual for their choices and their responsibilities, you probably want to either reject the premise that a structure is responsible for those outcomes, or at least redirect politics away from modifying that structure. You might have different reasons for wanting to do that. But for me, it starts to fall into that kind of politics where we're you know holding the individual responsible for something that may or may not be in their control. And I think it's very hard, and this is maybe why I come closer in my own biases towards the structural explanations. I think it's very hard to identify where my will and intent begins and ends, let alone where somebody else's will and intent begins and to ends. And so I always think it's helpful and better to look at structural explanations as a starting point and leave the like this person just chose to do this to themselves to the very end, as a sort of last explanation, rather than the other.
Cressida: 15:35
The last libertarian frontier. Yes. Yeah. Yeah. Really popular with students though.
Joshua: 15:41
Increasingly.
Cressida: 15:42
The libertarian instinct.
Joshua: 15:44
Yeah, I think that, you know, as the world becomes more and more complex as you move through education, there's maybe a strong inclination to just say, like, we're all just gonna I've got my section of things that I'm responsible for, and you've got yours, and that's what that's what I'm gonna do. And everything that happens to me, I'm responsible for, and everything that happens to you, you're responsible for.
Cressida: 16:10
Yeah, it gets nasty though, doesn't it? Because then it sort of turns into, well, if you hadn't eaten that junk food, you wouldn't have gotten cancer, so maybe we shouldn't be treating you. But you know, everybody gets cancer for some Everybody gets cancer. Yeah, for some cha Everybody gets cancer first, but B for some chain of reasons that can never really be pinned down because it's so complex and large and unknowable, and so the kind of attribution of health outcomes to individual behaviors is extra tricky, I think.
Joshua: 16:43
Mm-hmm. Yeah, and I think we we often see this as an explanation for for poverty.
Cressida: 16:49
Yeah.
Joshua: 16:50
Probably more so than anything else, but you can definitely map the explanations onto sleep health, normal health, dieting. And I think the same way that we should be suspicious about taking the responsibility for poverty off of society and putting it onto the person in poverty, we should be suspicious about how we're assigning blame for sleep habits and dietary habits as well.
Cressida: 17:21
Yes, the this is why we're anti-sleep tips.
Joshua: 17:24
Yes. Or why we're suspicious about the underlying work that sleep tips are doing. Yes. Right? In the way that they shift responsibility.
Cressida: 17:35
Yes.
Joshua: 17:36
Potentially.
Cressida: 17:37
They have a little libertarian flavor.
Joshua: 17:39
Yeah, there is just a whiff. Just a whiff.
Cressida: 17:42
That was a bit of an excursus. So maybe we need to turn to some more specifics. There were other areas of sleep health that our guests wanted to characterize as unfairly unequal. And our first example comes from Michael Grandner. Remember him? Who talks about racism and sleep disparities? And I asked him to explain how racial biases sneak into sleep and sleep research and how he advises racialized patients with sleep problems. So when we're talking about the social contexts of sleep, one of the things you said in an earlier kind of list was racism. We've thought a lot about health disparities asleep and these sort of axes of inequality or inequity in the podcast. And so I wondered if you wanted to say something about some of the mechanisms by which socioeconomic status race, which as we all know in social sciences is a terrible category, but ethnicity, let's say, other kinds of gender, age, and so on, where we're talking about difference across populations, but we're also talking about power, oppression, and social justice. Right. So, in those contexts, being um in Canada, being indigenous can have a terrible effect on your sleep. And when we're talking about behavioural modifications, it's not quite so obvious what one does because you can't you can't snap your fingers and end racism, you can't get out of it. Although we're not completely without agency when it comes to changing racist patterns. And so I guess there are two parts to it. What are the mechanisms through which health disparities are um where sleep is the mediating factor for health disparities that are linked to these other inequalities? And how do you think about that as somebody who practices behavioral medicine? Because you don't want to tell somebody who's the you know the victim of racism to you know not stop sitting on the couch, right? Like you can't sort of fix it so easily.
Michael: 19:58
Yeah, no, it's a it's a great question. And as somebody who does a lot of health disparities work, especially like as a white male who does health disparities research, which is which is complicated in its own way, you know, sometimes I've had to exert a bunch of effort to make sure that I'm aware of my own sort of biases in life, how my life experiences or lack of other life experiences sort of shapes how I do things. And and one of the things that that I often have to educate people about is the differences between differences and disparities. And there are such things as differences that aren't disparities, they're just differences. But sometimes differences can create disparities, but disparities are kind of differences that don't need to be there, differences that aren't inherent. You know, they're they're differences that we created.
Cressida: 20:52
Well, and the and that are unjust, right?
Michael: 20:55
Yeah, that put people in a situation that is disadvantageous by no fault of their own, by the fault of an organization, which means it should be corrected. It's not it doesn't need to be there. And that's sort of where the the justice part comes in. And so we see sleep disparities for a number of reasons. Sometimes it's differences. So, for example, you have sex differences in just sleep physiology that like men are more likely to get sleep apnea, women are more likely to get insomnia, you know, women are more likely to have to develop um more shallow sleep, you know, and there's there's menopause-related issues, but there's also disparities in that women are under different kinds of stress, and women have different access to different kinds of help. And most of the work that I've done is looking at racial, ethnic, and social socioeconomic disparities, and they're not the same thing. They overlap to some degree, but if you control for one, you'll see the other. One thing that's particularly interesting at least here in the US is we tracked um sleep using national level data showing that there is a slight you're talking about talking about the crisis you mentioned earlier there is a there is actually a linear slight decline in sleep it's it's smaller than people think at the national level but what we've one of the things we found was first of all the starkest sleep disparities in the population at least in the US are black white differences and I say black not African American because not everyone who's black is African American and but you know like you mentioned race being a social construct not really a a biological one but it's tricky because it's real because people act like it's real. Absolutely it it exists but it doesn't exist in the way people think it exists.
Cressida: 22:54
Yes well and it and it's a a moving signifier as well I mean what race means differs so much across time and place. Totally it has effects.
Michael: 23:04
Yes yeah and so there there are well documented especially black white differences in the US especially mostly African Americans but you do see this in some other groups as well but it's not a skin color issue it's a societal issue and some of it's socioeconomic but it isn't all socioeconomic. And what you see is there's this gap in sleep attainment that we've traced back you know as far back as we could find data was the 70s and it was there and it's been parallel until recently in which case it widened it's been widening there's another group in particular where the the relationship relative to white Americans is changing and that's Mexican Americans where traditionally going back sort of as far as we have data generally if you have a sample that includes Mexican Americans they will actually demonstrate somewhat better sleep than non-Hispanic whites um but that gap looks like it's now closed.
Cressida: 24:04
So we should we should clarify we're talking about sleep duration.
Michael: 24:08
Right now I'm talking about sleep duration because that's been the thing that's easiest to measure in large groups of people and what we were able to show was that those those were the two groups that had a significantly larger decline. And what we found was it was driven by an increase over time in people who are just habitual short sleepers that was driving that difference. And so why are people shorter sleepers in terms of differences in terms of sleep quality measuring sleep quality at the population level is super tricky. So we looked at some data a bunch of years ago looking at complaints insomnia complaints especially are tricky to measure across culturally because it doesn't mean the same first of all the the things don't mean the same thing but also there's different ways people react to questions. So for example this was data out of NHANES where we showed that if you ask people how often do you have difficulty falling asleep you know the group that was most likely to report difficulty falling asleep was white people like we're the complainers.
Cressida: 25:16
That sounds right!
Michael: 25:19
Yes yes we're the whiners and we're the complainers we we expect things to be how we want them to be yes and when they're not we get unhappy.
Cressida: 25:27
And have perhaps have a bit more space for making complaints like are less likely to be received with a stereotypical
Michael: 25:34
exactly and every other group especially black or African American and Hispanic and Latino where they didn't separate out Mexican American they were actually less likely you know they were they were at least 30% less likely to endorse them but separately they were asked on average how long does it take you to fall asleep? How many minutes? And if we dichotomize a 30 minutes which is usually what we use as a clinical rule of thumb as a cutoff actually if you were black or or Latino you were twice as likely to take at least 30 minutes to fall asleep. And it's it's because we have a face validity problem in sleep quality because it's so culturally bound. Like the idea of what does sleeping well mean yes what does what does takes too long mean? Like insomnia was invented by white people to express their dissatisfaction insomnia is a dissatisfaction. Insomnia isn't it takes me a long time to fall asleep insomnia is it takes me too long to fall asleep. And those determinations are very influenced by context. And so we we've run focus groups about this and asked people like what do you mean difficulty? And they'll say well if I can get up to go to work put food on the table and do what I need to do it's not a difficulty. I can handle it. But if it starts interfering with my ability to function then it's a difficulty but I think I'm functioning fine.
Cressida: 27:04
Yeah for sure.
Michael: 27:05
Versus you have the more Eurocentric introspective individualistic perspective of it's unpleasant to experience in the moment therefore it's a difficulty. So like our frame of reference for what we how we describe sleep quality is just so fraught as a field we just have not tackled this yet. We have not wrapped our head around how to ask the questions correctly. So we default to things that are a little easier to quantify. That's another reason why sleep duration does a lot of the heavy lifting in the conversation. Not because it's the best metric but because it's kind of the most stable.
Cressida: 27:43
So I guess my my question is as a clinician how do you think about that? Because I mean I think it's only good political thinking to be aware of all of these factors. But when someone comes into your clinic maybe this doesn't happen but I think it probably does and they say you know I I'm responsible for six kids and I'm making a minimum wage and I have to work sometimes I have to work night shifts and it's so hot now but I can't afford air conditioning. How do you help that person?
Michael: 28:16
Where the typical medical model is well then you know the solution is get a better job, right?
Cressida: 28:21
yes yeah yeah That can't be a solution.
Michael: 28:25
But the point is because it's first of all because it's bi-directional like where where poor sleep also contributes to inefficiency of your productivity which is going to decrease your success and all these sorts of things. There's lots of groups that face all kinds of constraints. Some of those constraints are long lasting I mean there's great data that shows that people exposed to racism have less stage three or what we would call deep sleep as adults just even if they're you know higher socioeconomic status as adults like you can have these trajectory changes. It's not even just your current situation. So there's a few ways I do I manage this in clinic one is first of all recognizing that I'm seeing these things as relevant and sometimes people don't expect that that that a clinician is actually going to see those things as not just inconveniences or barriers but as real like actual components to their situation. So for first of all it's that second of all I I can't fix those things. I mean sometimes you can try and get access to resources or whatever but that's usually not something I can I like if those problems could have been fixed these people aren't idiots they would have fixed them already.
Cressida: 29:47
Right, right.
Michael: 29:48
One thing I can do is help people sleep a little bit better in this context which can help better prepare them to manage the stresses of of life sometimes the way in is the other way. Sometimes the way to make these experiences less of a burden is to help you get sleeping a little bit better so that you're better able to manage and maybe you'll find some other solutions that you couldn't see because you were so tired. Sometimes it's sleep first. The other thing is sometimes there's certain adaptations and modifications you need to make to some of the typical sleep recommendations and behavioral interventions that adapt to those environmental and situational constraints. I mean lots of groups have constraints that you need to make into adaptations to lots of occupational groups I mean truck drivers I work with a lot of athletes athletes also of different types of different types of crazy schedules shift workers of all kinds I mean doctors and nurses are also shift workers but in a different socioeconomic level but they're still dealing with some of the same sleep issues so if you're dealing with a person well what is it that we're trying to accomplish here and how do we leverage the the scientific principles that underpinned the recommendations to apply them to this situation. If we applied them in this situation how would the recommendations look different? Because the recommendations are based on certain assumptions about people's environment yeah and that's why a number of us are trying to figure out what are the correct adaptations and modifications and ways to decide when to use them. Like you're sort of developing a new intervention based on the old intervention but you're not starting from the old destination you're starting from the original source and where it takes you. But let's say someone um or like I have to get up at five o'clock in the morning and my body wants to get up at nine but I can't do that. Now what? What how am I gonna can I is it about shifting a rhythm?
Joshua: 31:51
Is it about optimizing the sleep you can get is it about scheduling a nap later in the afternoon when you have a break like what are the different things we can do to meet those situational constraints whatever they happen to be that's a great clip with with so much to think about insomnia was invented by white people is just a an incredible phrase that is gonna just rock around in my brain for a while.
Cressida: 32:32
Yeah right I we're doing an episode on insomnia everybody so don't worry we'll come back to it. Finally yeah yeah we've been resisting but we but we're doing insomnia a bit later in the season. So if we talked a bit about race now it's time to talk about gender and age and we turn to Roxanne who's been thinking about why sleep disparities particularly affect women then she goes on to talk about why sleep in adolescence and young adulthood is another hotspot of sleep struggle.
Cressida: 33:11
So you wrote a really powerful piece for Ms magazine last year that had the headline sleep is a feminist issue. Awesome we agree over here what did you mean when you said that ?
Roxanne: 33:18
I meant that a lot of the reasons women aren't sleeping as well I should say both women and genderqueer folks are at the policy level. So a lot of these policies reflect classism racism sexism and that the solutions are much more systemic, right? So we don't have nearly enough research dollars invested in things that impair sleep in women so a lot of the transition through menopause a lot of the menstrual pain and fibroid pain like that's so poorly funded and really cost a lot of women days every month of excruciating pain and that's just hasn't been researched or funded. And then don't get me started in the United States on how poorly we support parents especially new mothers like we we don't have paid parental leave right that's shocking. That's really shocking. You get six weeks unpaid disability six weeks of not being able to lose your job if you work one of these particular jobs that has that otherwise you could be fired. So it's so many structural pieces are in place that just will make it impossible to get good sleep because you're also trying to make sure that your family is safe that you're you know have money to keep the the heat on and groceries.
Cressida: 34:57
So you've done a lot of research as well as public engagement on sleep through different stages of the life cycle and I watched your TED talk Sleepless in school addressing our children's sleep debt very good I like that one and you wrote a 2019 article which is very bluntly but accurately I think titled "Sleep Predicts Collegiate Academic Performance." I'm like yeah no shit and so that article has a very striking first paragraph so you're drawing on Mary Cascaden, the sleep researcher who described sleep in adolescence as the "perfect storm of factors that impair sleep, a biological phase delay and decreased sensitivity to the homeostatic sleep drive coupled with that delay sleep and necessitate early wakening. These conditions have created a generation of young adults who enter college without an embodied understanding of what it feels like to be well rested." Wow. So can you maybe start by explaining what these technical words mean these three factors?
Roxanne: 36:05
Sure and I'm sure as soon as I explain them your listeners will be like oh that makes perfect sense or I remember that.
Cressida: 36:11
Yes.
Roxanne: 36:12
So the first one the biological phase delay is very simply that there is a biological reason that teens stay up later than little kids and later than adults right so I have a And my I'm rolling my eyes because I have a teenager. Yep I have a 16 year old and we recently yeah we we we go to sleep hours before she does and there's nothing we can do to change the biology of this so it's it's everything that we can measure. It's when your body temperature cools down for sleep it's when your melatonin kicks in it's when your cortisol drops all these factors in adolescence and not just in humans this happens in adolescents and in other mammal species just stay up later right so that is the biological phase delay and this kicks in earlier for girls usually than for boys but also that means that boys take longer to get back their their normal rhythm. So that is the biological phase delay basically saying that high school students and young college students find it really difficult to get up at seven for an 8 a.m class . The second is decreased sensitivity to the homeostatic sleep drive so when we want to go to sleep when our bodies sleep is a combination of a couple factors one is how tired we are and another is our circadian rhythm. So I talked about the circadian rhythm with the phase delay. So I'm a morning person I wake up five to six without an alarm clock it's just what my body does I wish I could sleep in but I can't that is like 60% of my body's genes are under this like circadian control that has its own time rhythm that determines when I feel alert when I feel sleepy when I feel grouchy. The second factor is just how tired we are that is the homeostatic sleep drive so and this can be influenced by a number of things like if you have a really hard day if you do like a speed chess tournament and then a marathon your body and brain are going to need a lot of sleep to recover from that. So that's the homeostatic sleep drive so what what teens have the ability to do is withstand sleepiness. I was just visiting a friend from college this weekend and she and I we love soccer but we couldn't stay up for the second half of the World Cup games like the last game we were just like well right Scotland will either win or it won't but I gotta go to bed right so but we were joking when we were in college we went to movies that started at midnight yeah right like so teens don't feel sleepy in the way that I feel sleepy. So they have reduced to be true. Yeah like I could not hang like I I did when I was a teenager. So that's part two. It's just it's harder for their body to feel the tiredness that I really have now in my life.
Cressida: 39:21
Yeah.
Roxanne: 39:23
Zeitgeber so German word for time giver and if you're a German speaker I'm sure I'm not getting that correct precisely. But it's the idea that there are cues in the environment that tell you when it's time to be awake and when it's time to be asleep. And for the 2000 years or so of of Homo sapiens life on earth that was a real clear and easy signal right the sun was either there or it wasn't right it's warm and sunny or dark and cold. And so this is probably the thing that's changed most in human history is what our Zeitgebers are. So yes there's the electric light that is a really powerful communicator to your brain about whether you should be awake or asleep. The eyes connect to over 13 different spots in the brain and only one of them is conscious what can I see? The other 12 are non-conscious responses to light hormonal responses to light like very primitive body responses to light. So light is is a powerful stimulus for that. So we've got the electric light revolution for the last hundred or so years. And after that now we're living in the attention economy right so we've got these all these apps that are are programmed to grab us to get us like thinking that we should be paying attention to something buying something studying something communicating with something 24/7. So these are the Zeitgebers that these teens are dealing with their entire social brain is attuned to the world all the time that's available on their phone. So it's hard when you see all that activity for your brain to think oh it's nighttime not when you can see what your friends are up to literally in real time with tracking data and the posts that they have and and so we've lost the cultural signals to say it's nighttime go to bed and we're awash in external and like personal signals to stay awake.
Cressida: 41:44
So it's sort of a relief that Roxanne explains as you get older your homeostatic sleep pressure increases. I thought it was just me. I thought I crash out on the couch in the evenings and it's you know obviously some personal failing but that the desire to go to sleep in does feel more pressing as you get older. Hearing it described as pressure really makes sense I think it's also very intuitive for different reasons to me to suggest that there's a biological phase delay for young adults that's part of the sleep problem. And that is a problem of course only really because of cultural norms about school start times.
Joshua: 42:26
Yeah and young people have a compounding problem because they also have very distinctive time cues aka phones and how they affect their sleep is really a cultural preoccupation.
Cressida: 42:40
Yeah so certainly as the parent of a teen it's a news story that seems to be everywhere all the time the effect of phone use on teen sleep and probably rightly so because it's a huge cultural shift the generation that are teens now are the first generation to grow up with their own cell phones that had social media content available to them all the time and this has been a really big topic of conversation in the public discourse about sleep so we asked our other guests about it.
Joshua: 43:10
Yeah I asked Lauren whether she thought that digital media apps and streaming services were essentially anti-sleep devices and also what one policy change she'd like to see to improve sleep health
Joshua: 43:33
Like is it fair to call the phone and those applications like anti-sleep devices and there isn't really a way to reconcile them with healthy sleeping?
Lauren: 43:52
That was even before net the Netflix CEO said that even before people were watching it on their phones it was like an early quote by the CEO before there were so many other streaming apps. Now I think they probably recognize there's other competition out there.
Joshua: 44:07
Right, yeah, yeah.
Lauren: 44:08
Um I think I haven't used the term anti-sleep before, but yeah, I would say that's a pretty fair assessment. They are at least not conducive to sleep. There are, of course, apps designed to facilitate sleep and meditation apps, and those might fit into a different category. And again, if they work for you, I'm okay with that, unless the presence of the phone gets you checking your favorite social media account right before you shut your eyes. Or you know, like I'm okay with it to the extent that they work. But if they don't work, we have been sleeping, you know, not just we, all the creatures of the world have been sleeping pretty well without, you know, apps and devices to help us sleep. And I would say that would be optimal. But if if you're using an app, and I'm not promoting any particular one, if you're using one that works, then then that's fine. But I would be mindful about not using the device for other things that might work against sleep.
Joshua: 45:22
If we want to make sleep oases, then what would be sort of the the biggest leverage point for policy if we were interested in making like better sleep environments? What would be what would be the best policy move?
Lauren: 45:38
Okay. So the it's not necessarily the easiest, but I would go with the one that has an immediate big impact and affects everyone equally, is later school start time.
Joshua: 45:56
Really?
Lauren: 45:57
High school students should not be starting school before 8:30 in the morning, and yet, with the exception of California, 80% of high school students do. So there are decades worth of studies showing the benefits of later school start time for teenagers. And there's really no reason why it's not a federal policy. Only one state in the country has changed their mind on this so far. They did it, unfortunately, right in the middle of the pandemic. That was California. So we're still rolling out the results, but preliminary evidence from my colleagues that are not yet published, so I'm going to be quiet about who and what the magnitude is, confirm exactly what we expected. That kids who live in California after later school start times are sleeping much longer than those who were going to high school before the rollout. And this happens at a local level all around the country, but there's a lot of resistance to changing school start times. And it's a frustrating challenge to overcome, but totally worth it.
Cressida: 47:19
Okay, well that's about it for today. We've gone from why we sleep, to the interaction of sleep and culture, to how our sleep health is a product of bigger pictures than we know, to ideas about better policy. It's been a lot of ground and a slightly different approach for us.
Joshua: 47:36
We hope you'll come back in two weeks for our next episode. In the meantime, you can find past episodes, show notes, and transcripts on our website sleepsthenewsex.ca. Thanks for listening. Please do follow and rate us.
Cressida: 47:51
This series is recorded at the University of Alberta, which is located on the territory of the Nehiyaw, Niisitapi, Metis, Nakoda, Dene, Haudonosonee, and Anishanaabe, lands that are now known as part of Treaties 6, 7, and 8 and homeland of the Metis. As we talk about the history and meanings that sleep, rest, leisure, and productivity have for us, we also want to recognise the way each of these ideas participates in the history of colonialism that is shaped and continues to shape relations between settlers and First Nations. Our sound engineer is Tom Merklinger, who also wrote and performed our music. To find our first season, please see the link in the show notes, and for more information on this project, visit sleepisthenewsex.ca
Pete Holmes: 48:49
Explain sleep to an alien that doesn't sleep. I couldn't do it. I could explain food. I could be like, I need energy, so I eat an apple, so I can use the energy that's in the apple. He'd be like, okay. Anything else? Yah. At night. Regardless of how much energy I 've consumed, I just have to shut it down. I shut it down, for like, 8, 9, sometimes 12 hours. Sounds boring. No. My brain plays movies that I'm in. Sometimes they're scary!