About the SA Blog Network



Opinion, arguments & analyses from the editors of Scientific American
Observations HomeAboutContact

Sleepy Teens: High School Should Start Later in the Morning

The views expressed are those of the author and are not necessarily those of Scientific American.

Email   PrintPrint

High school begins across the U.S. this week and next. And it begins too early! Too early in the day, that is. Ask any groggy teenager waiting for a bus or yawning in “home room” and he or she will tell you that it’s just too darn early in the morning to learn chemistry equations or analyze a narrative by some Russian novelist.

Are they just lazy? No. Scientific studies of teen sleep patterns say they’re right. So do results from numerous schools across the country that have delayed start times: The later classes begin, the more academic performance improves. Bonus points: attendance goes up, teen depression goes down, and fewer student drivers get into car crashes.

Seeing the mounting evidence, the American Academy of Pediatrics yesterday released a new policy statement recommending that middle and high schools delay the start of class to 8:30 a.m. or later. Doing so will align school schedules to the biological sleep rhythms of adolescents, whose sleep-wake cycles begin to shift up to two hours later at the start of puberty, the policy statement says. The conclusions are backed by a technical report [pdf] the academy also released yesterday, “Insufficient Sleep in Adolescents and Young Adults: An Update on Causes and Consequences,” which is published in the September 2014 issue of Pediatrics.

The “research is clear that adolescents who get enough sleep have a reduced risk of being overweight or suffering depression, are less likely to be involved in automobile accidents, and have better grades, higher standardized test scores and an overall better quality of life,” said pediatrician Judith Owens, lead author of the policy statement, titled “School Start Times for Adolescents.”

The debate over whether to start school later has run for years, but a host of new studies have basically put it to rest. For one thing, biological research shows clearly that circadian rhythms shift during the teen years. Boys and girls naturally stay up later and sleep in later. The trend begins around age 13 or 14 and peaks between 17 and 19. The teens also need more sleep in general, so forcing them to be up early for school cuts into their sleep time as well as their sleep rhythm, making them less ready to learn during those first-period classes.

Practice is proving the science. Hundreds of school districts in the U.S. have experimented with later start times and the academic performance of students has improved across the board. A study [pdf] released in February that tracked 9,000 high school students in three states showed that grades in science, math, English and social studies all rose when school began at 8:35 or later. Controlled experiments with different start times among the same classes of students at two North Carolina high schools and among the freshman class at the U.S. Air Force Academy also showed that academic performance improved.

The later the start, the better the result, too, according to Kyla Wahlstrom, director of the Center for Applied Research and Educational Improvement at the University of Minnesota. She published the study of the 9,0000 students. Delaying the opening bell from 7:30 a.m. to 8:30 a.m., for example, paid off more than delaying only until 8:00 a.m. Research indicates that students who get at least eight hours of sleep, and preferably nine, perform better than those who do not, Wahlstrom says, so a greater delay raises the chances of achieving those numbers.

School districts may balk at such a large adjustment. But Wahlstrom says any change “will create some amount of community disruption, so there’s no real reason to make only a small shift; make the bigger shift and get the maximum benefit.” Most districts find that a change entails a full year of disruption, she say, “but then they don’t want to go back,” because the benefits are so tangible. The biggest resistance is just resistance to change, she says. “We’re into homeostasis.”

What’s more, communities find that the usual worries about starting school later do not pan out, according to an analysis by the National Sleep Foundation. Students still succeed in holding part-time jobs, and after-school programs such as sports and theater still run well. “I get tired of the argument that these kids have to do all these activities and community service and therefore can’t start school later,” Wahlstrom says. “The issue is not the start time. It’s that the students are overly busy. There is too much pressure to cram it all in just to have a good resume to get into college.” Students, parents and school advisors should all be more judicious with what students choose to participate in, she says, with emphasis on doing certain activities well rather than piling up a long list.

Studies in other countries such as Brazil, Italy and Israel also show that later start times improve learning. Across Europe, the equivalents of high school rarely begins before 9:00 a.m. “Europeans are shocked that Americans start so early,” Wahlstrom says. According to the pediatricians’ academy, 40 percent of U.S. high schools start before 8 a.m., and only 15 percent start at 8:30 a.m. or later.

If school districts and parents are still not convinced, data about car crashes may make them take notice. Controlled studies are difficult, because so many factors are involved: the age of drivers varies within a school district, school districts with different start times have different mixes of students. But a few studies stand out. In Jackson Hole, Wyoming, for example, there is only one high school within a hundred mile radius. Delaying the start time from 7:35 a.m. to 8:55 a.m. correlated with a 70 percent reduction in car crashes among drivers ages 16 to 18.

Another intriguing study was done more than 10 years ago by University of Kentucky researchers. In Fayette County, which has only one school district, crash rates of teen drivers dropped 16.5 percent in the two years after start times were delayed one hour, compared with the two years before the change. The kicker: the teen crash rate for the rest of the state went up 7.8 percent in the same time period. Sure enough, the portion of Fayette County students who got at least eight hours of sleep during weeknights rose from 36 percent to 50 percent, and those who got at least nine hours rose from 6 percent to 11 percent.

Nonetheless, more comprehensive results are needed before fewer accidents can be reliably linked to later school start times, Wahlstrom says. But anecdotally, the idea makes sense. “Driving is monotonous,” she notes. “So if you’re sleep-deprived, you’re more likely to lose attention, have your head nod or fall asleep at the wheel.”

Photo courtesy of gydnew on Flickr

Mark Fischetti About the Author: Mark Fischetti is a senior editor at Scientific American who covers energy, environment and sustainability issues. Follow on Twitter @markfischetti.

The views expressed are those of the author and are not necessarily those of Scientific American.

Rights & Permissions

Comments 23 Comments

Add Comment
  1. 1. JackSprat 9:22 am 08/26/2014

    I was a high school teacher when a new superintendent came in bearing research with the same conclusions and this was 14 years ago, so we changed the high school schedule so that school didn’t start until after 8 am and it didn’t make a hill of beans difference, you know why, the kids told us why: THEY JUST STAYED UP LATER BECAUSE THEY DIDN’T HAVE TO BE TO SCHOOL UNTIL AFTER 8 AM! Students who worked chose to work later, even signing up to close down their fast food restaurants at 1 am because they could “sleep in”. Thomas Jefferson once stated that in all his time at Monticello the sun never beat him out of bed (his bed faced the east rising sun and he had a window placed there where the sun comes up), and it seems not to have stunted his growth. So if these schools that are applying this research finding can also get their students to all go to bed early enough to get the requisite sleep then this might work, otherwise it’s a waste of effort!

    Link to this
  2. 2. davecons 9:38 am 08/26/2014

    JackSprat: This is exactly correct. I am a high school teacher and we made our start time later in the morning. Attendance actually got WORSE because not only did students just stay up later (and admitted to me as much), but they were now driving in rush hour traffic as opposed to earlier in the morning.

    Also, this article doesn’t say much about how large the improvements are. Are they even statistically significant? Are they long lasting? By that, I mean that the students might “get used to” the later start time by just staying up later, and then the gains might be lost.

    Show me the data or else no dice.

    Link to this
  3. 3. LoGca1 10:35 am 08/26/2014

    Check the test scores of schools that start at 7:45am or 8:00am against those that start at 9am. I will bet the early risers beat out the sleep-ins.

    Sure start high school at 9 or 10am. Then no college class start before 11am.

    Then after college they can find a great job that starts at 12 noon on Wall street… Delivering lunches (with their BA in their back pocket); from a sandwich shop that works them from 12 to 2pm!

    We have too many teens now that are nonfunctional in our society.

    This is an idiotic idea.

    Link to this
  4. 4. popseal 1:52 pm 08/26/2014

    Early to bed and early to rise, makes a man healthy, wealthy, and wise. Ben Franklin Arriving early and staying late are two elements of business success. your next boss If you’re on EBT cards you can sleep all day. Popseal If a man doesn’t work neither should he eat. St. Paul

    Link to this
  5. 5. twinglestar 10:42 pm 08/26/2014

    It seems logical, however, if I don’t have to get up earlier, I definitely stay up later.

    Link to this
  6. 6. dubina 12:41 am 08/27/2014

    I have kids who stay up late to play video games and troll Facebook. They sneak out of bed to do it. Late to bed is a discipline problem and a problem of self-restraint. I saw this solution: “Sleepy Teens: High School Should Start Later in the Morning” promoted on one of the news programs a few days ago. The woman who promoted it ignored the fact that the kids were out of control, implying nothing else to do but cater to their bad habits.

    I don’t think so.

    Link to this
  7. 7. Brando56894 11:59 am 08/27/2014

    I’m going to assume that all of you are morning people because if you were a “night owl” you definitely wouldn’t be responding that way. I have insomnia on top of being a night owl so I don’t get tired until at least midnight or 1 am, no matter what time I wake up that morning. I would wake up at 6:30 am, roll out of bed half asleep, walk to school, then sit in math class for first period. I couldn’t stay awake enough to pay attention, let alone do complex math. If you guys think this is BS, let’s see you wake up at 6 am and then start doing homework or any sort of mentally draining work at 1 am or later and lets see how well you do at that work, you would most likely be so tired and drained that you wouldn’t be able to focus, that’s how we feel in the morning.

    Link to this
  8. 8. dubina 5:18 pm 08/27/2014

    @ Brando56894

    Consider this.

    Pushing back the start of the school day would necessitate wholesale change in the caregiver adult work day.

    Let’s get real.

    Link to this
  9. 9. ERTERT 6:20 pm 08/27/2014


    Link to this
  10. 10. ERTERT 6:23 pm 08/27/2014


    Link to this
  11. 11. evelyn haskins 10:08 pm 08/30/2014

    I’m sorry. But I cannot understand WHY you would be starting school before 9am. Especially in the Higher latitudes where you will be expecting the kids to leave home in the dark!
    Nor why you would be starting college later than school?

    Yes, I can remember 8 am classes, but these were for elective subjects and were my choice.
    Other kids would get up to do their swimming or sporting practice earlier, but once again these were elective.

    Link to this
  12. 12. hkraznodar 6:27 pm 09/4/2014

    So, teachers that aren’t very good dislike the idea of early start times. (Sorry, but the terminology you use gives you away. I’ve know too many good and bad teachers to miss the patterns.)

    People that comment on articles without actually reading them don’t think that later start times proven to improve scores actually improve scores. The painfully obvious is um, painfully obvious.

    Popseal is still incoherent and dubina admits to a failure to control her own children. Dubina also knows nothing of history and the multiple times the adult caregiver work day has been drastically altered to generate vast wealth for a handful at the expense of the majority.

    Ignorant criminals are still allowed to spam the blogs without repercussions. (ERTERT)

    Thank you Brando and Evelyn for actually addressing the issues of the article without resorting to meaningless anecdote. With all of the moaning about how bad our schools are, despite the evidence that they are much better than they used to be, one would think that adapting to the systems used by countries that significantly out perform our own schools would be a popular idea.

    Link to this
  13. 13. CimdyMom 8:20 am 11/9/2014

    I cannot understand why there are so many parents who ignore this problem and don’t try to change something. Actually, it is very difficult to influence the situation. However, he number of stressed children with various health problems prove that it is high time to change something. I have never thought about it as it was a kind of tradition. But, when I saw my daughter with red eyes and trembling hands, I realized that we have to something. Last time when she stayed awake for a long time, we applied to for help with her papers. I think that there is nothing more important than health.

    Link to this
  14. 14. TheTruth22 8:54 am 11/19/2014

    You people who disagree with this are obviously self-centered and clueless. This is an GREAT idea! what about the athletes who play games that are an hour or more away? They don’t get home until after 11 P.M. almost 12 A.M. and to top it off they still have homework, tests, and projects. All teenagers don’t focus their life around video games; they actually have real scenarios going in their life causing them to lose sleep and become stressful. Many are failing because they are too tired and decide rather to sleep than do work! Think about it people

    Link to this
  15. 15. getalife21 2:06 pm 12/9/2014

    gay get a life

    Link to this
  16. 16. Maryfernando12 12:04 am 01/14/2015

    Lamentably, I am excessively acquainted with the effect of right on time begin times. Our school area’s secondary school begin time is among the soonest in the country (7:10 a.m.) and my 15 year old child battles with it once a day. In spite of my earnest attempts, he seldom gets enough rest on the grounds that his science is changing and that is influencing his slumber designs. I’m pleased to say I marked the request. I trust this national activity is fruitful – for the wellbeing and securely of my youngster.

    Link to this
  17. 17. shirleydevis 2:54 am 01/14/2015

    Study is self-guided for the hypothesis segments, however you’ll have admittance to our online group of qualified and experienced mentors, in addition to backing from your kindred understudies.

    Link to this
  18. 18. SunnyEssays 3:23 am 02/17/2015

    Grievously, I am exorbitantly familiar with the impact of right on time start times. Our school region’s optional school start time is among the soonest in the nation (7:10 a.m.) and my 15 year old tyke fights with it once a day. Regardless of my sincere endeavors, he sometimes gets enough rest because his science is changing and that is impacting his sleep plans.’m satisfied to say I denoted the solicitation. I trust this national action is productive – for the wellbeing and safely of my young perso

    Link to this
  19. 19. michaelrodgers 12:04 am 02/24/2015

    I am very much agree with that high schools classes time should be at 9.00 am morning. So they can get proper sleep instead of yawning in the class room.

    Link to this
  20. 20. Slavon 2:31 pm 03/14/2015

    The best kidkraf totys for kids including vintage kitchens in blue find here.

    Link to this
  21. 21. BuyAssignmentService 3:53 am 04/3/2015

    It appears to be legitimate, then again, in the event that I don’t need to get up prior, I doubtlessly stay up later.Students Help Service

    Link to this
  22. 22. abellacolbert 2:01 am 04/9/2015

    If you become a superintendent, you’ll work closely with clients to evaluate their High school, Start times and improve their Different start times.
    Nice Post
    For more details you can visit:

    Link to this
  23. 23. TaniaWilson43 8:59 am 04/9/2015

    If you’ve watched the news this year, then you probably have a good idea how important this Applied Research and Educational Improvement.
    For more details you can visit:

    Link to this

Add a Comment
You must sign in or register as a member to submit a comment.

More from Scientific American

Email this Article