GUY RAZ, HOST:
So, Wendy, Sam Kass was talking obviously about food and how it could change schools. If I were to ask you to give me one idea about something that could have a huge impact on kids in schools, what would it be?
WENDY TROXEL: More sleep.
RAZ: More sleep - that could actually have, like, measurable impact on, like, how well students do at school.
TROXEL: Absolutely, and we have evidence to bear this out.
RAZ: This is Wendy Troxell.
TROXEL: I'm a clinical psychologist, sleep medicine specialist, and I'm a senior and behavioral social scientist at the RAND Corporation.
RAZ: And Wendy's research focuses on teenagers, so high school-age kids. And she says the results, well, they're pretty clear.
TROXEL: Kids who get adequate amounts of sleep perform better in school. They're more likely to show up for school on time, have better graduation rates. They're able to think and perform better. Their attention is better. Kids who are sleeping sufficient amounts also have better mental health and physical health, all of which we know goes into the factors that contribute to a whole, healthy child who's able to perform and succeed in school.
RAZ: Now, this may sound painfully obvious, right? Kids need more sleep. But it's not that easy, as Wendy Troxel explains from the TED stage.
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TROXEL: Sleep deprivation among American teenagers is an epidemic. Only about 1 in 10 gets the eight to 10 hours of sleep per night recommended by sleep scientists and pediatricians. Now, if you're thinking to yourself, phew, we're doing good, my kid's getting eight hours - remember, eight hours is the minimum recommendation. There are many factors contributing to this epidemic, but a major factor preventing teens from getting the sleep they need is actually a matter of public policy, not hormones, social lives or Snapchat.
Across the country, many schools are starting around 7:30 a.m. or earlier, despite the fact that major medical organizations recommend that middle and high school start no earlier than 8:30 a.m. These early-start policies have a direct effect on how much or really how little sleep American teenagers are getting.
RAZ: I mean, basically what you're saying is that because school starts so early for teens and they have to wake up, you know, obviously much earlier than that to get ready for school and sometimes to even get to school if they're, you know, if they're walking or taking the bus, so of course they're not going to get enough sleep.
TROXEL: Exactly. It's a simple math problem, right? If you have a school that's starting at 7:35 a.m., like my own child's, that means that they're getting on a bus between 6:30 and 6:45 a.m. often. So if you simply back up the clock, your child has to be going to bed by 10:00 p.m. at the latest. And that's simply not possible for most teenagers. But the truth of the matter is all of this is truly an artifact of a decision that was made years and years ago frankly before sleep research was really as robust as it is today and before we knew the consequences of sleep loss that occurs in adolescence. So we're setting them up for failure - failure in their ability to sleep and failure in their ability to perform well at school.
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TROXEL: Adolescence is a period of dramatic brain development, particularly in the parts of the brain that are responsible for those higher order thinking processes, including reasoning, problem solving and good judgment - in other words, the very type of brain activity that's responsible for reining in those impulsive and often risky behaviors that are so characteristic of adolescents. In fact, many of the - shall we say - unpleasant characteristics that we chalk up to being a teenager - moodiness, irritability, laziness, depression - could be a product of chronic sleep deprivation. Around the time of puberty, teenagers experience a delay in their biological clock, which determines when we feel most awake and when we feel most sleepy. This is driven in part by a shift in the release of the hormone melatonin. Teenagers' bodies wait to start releasing melatonin until around 11 p.m., which is two hours later than what we see in adults or younger children. This means that waking a teenager up at 6 a.m. is the biological equivalent of waking an adult up at 4 a.m.
RAZ: So teenagers' biological clocks are delayed by about two hours.
TROXEL: That's correct, sort of like how you might feel if you travel, you know, west to east and your brain still is on the on the West Coast time zone but local time says, oh, well, it's locally 10 p.m., but your brain thinks it's only 7 p.m. You can't make yourself go to sleep at a time when your brain's not ready. And it's that conflict between the internal biology of adolescence and sort of clock time that poses the real problem.
RAZ: So this seems like - I mean, out of all of the problems that we're talking about on the show, this seems like the easiest one to solve, like the most doable. You just change the start time of schools. You just go to schools, and you say, hey, schools, you know, move your start time from 7:30 to 8:30. And you're done, right?
TROXEL: Yes. And I really wish it could be that easy. And, yes, if I was only a sleep researcher, if I hadn't been involved kind of with boots on the ground in districts where we've actually tried to get this done, I would have the same attitude because it should be a no brainer. However, the truth of the matter is start times really can have ripple effects on the entire community.
So there are legitimate concerns when you shift the day later for any group of students, you have an impact on other students. And if you're dealing with a tiered bus system, somebody eventually has to go first. And people are going to get out later. So there are many implications.
When we shift start times, there are impacts on after-school sports and other extracurricular activities. There's issues of care for younger children, both before and after school. There's also issues of afterschool jobs and other factors, such as traffic and transportation-related issues. So as much as it seems like a no brainer, it's not as simple as it sounds.
RAZ: Well, see now, I feel like you've just made a really compelling argument against your original argument. Like, now I'm like, yeah, I think Wendy's wrong. I'm with the school districts here.
TROXEL: (Laughter) Well, then, can I tell you about the consequence of early start times...
RAZ: Yeah, yeah, please.
TROXEL: ...Because, frankly, yes, you're right. If it was all about what's most convenient for adults, then keep the status quo, right? But what we know is that when schools start later - one school district found a 25 percent reduction in school absences. You know, school attendance is critically important for big issues like reducing the achievement gap.
When we delay start times, children are actually more likely to get the bus. And for many of our low-income students or racial and ethnic minority students - if bussing is their only option for transportation - if they miss that bus, they are not likely to go to school. So when we delay start times, we see an increase in attendance rates. We also see an increase in graduation rates. This has a direct impact on their lifetime earnings.
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TROXEL: Teens from districts with later start times get more sleep. To the naysayers who may think that if schools start later, teens will just stay up later, the truth is their bed time stay the same, but they're wake up times get extended, resulting in more sleep. Not surprisingly, they do better academically. Standardized test scores in math and reading go up by 2 to 3 percentage points. That's as powerful as a reducing class sizes by one-third fewer students.
Their mental and physical health improves, and even their families are happier. I mean, who wouldn't enjoy a little more pleasantness from our teens and a little less crankiness? Even their communities are safer because car crash rates go down - a 70 percent reduction in one district. The findings are unequivocal. And as a sleep scientist, I rarely get to speak with that kind of certainty.
RAZ: I feel like this period - like, the teenage period in our lives is where our biology requires a specific schedule, right? Like, it seems so obvious that we should figure this out, you know, to change our institutions and our environment to accommodate that.
TROXEL: Exactly. And one of the things I often hear - I hear the comment, oh, let's stop coddling our teenagers. They need to toughen up. We need to get them ready for the real world. But that's missing the point that this is a developmentally-specific issue. They don't have these shifted sleep-wake schedules for the rest of their lives. It is only during adolescence.
Similarly, like if you look at how you treat sleep in your younger child, we recognize that younger children have specific sleep needs. And we honor that, for instance, by allowing them to nap. We don't say, though, well, you know, this 2-year-old, we shouldn't let him nap because eventually he's going to be going to kindergarten, and he won't be able to nap in kindergarten. We know it's developmentally specific. A 2-year-old needs a nap.
You know, sleep science has clearly shown that there is this change in sleep-wake cycles such that adolescence naturally go to bed later and sleep in later. So by depriving them of sleep in adolescence, we are not doing anything to toughen them up. We're just hurting them in this critically important developmental phase. And the truth of the matter is by trying to kind of overcome this biology and putting a start time that's in direct conflict with their biology, we're really hurting their chances for success and their health.
RAZ: Wendy Troxel, she's a clinical psychologist who studies sleep. You can see her entire talk at Ted.com. On the show today - ideas about how simple solutions can be the answer to some of our most complex problems. I'm Guy Raz, and you're listening to the TED Radio Hour from NPR.
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