Science-- there's something for everyone

Monday, September 7, 2015

Start your senior year at 11:00 am?



It turns out that teenagers were right all along when they complain that high school starts too early. That actually isn't news to anyone who has had to drag an adolescent out of bed in the morning. However, the recommendations made by Paul Kelley of Oxford University and his colleagues may surprise you. They suggest that 18 year olds start school at 11:00 am.

First though, why is it that teenagers have so much trouble getting out of bed in the morning? The simple answer is that they can't get to sleep at night. This isn't a demonstration of lack of character but rather of biology, or more specifically of circadian rhythms. Every cell in our bodies is tuned to a 24 hour cycle, and the master controller for all our cells resides in the hypothalamus. The sleep-wake cycle happens to be an extremely vulnerable part of that 24 hour cycle. Throughout the day, we excrete competing hormones and neurotransmitters that increase either alertness or sleepiness. In adolescents, it just takes longer to reach a critical mass of sleepiness signals than it does in older adults. Thus, going to bed earlier doesn't help teenagers get more sleep. They are wide awake until late in the evening no matter what time they go to bed.


This means that when students get ready for school in the morning, they're likely to have had much less sleep than they need. A typical 15 year old gets less than 7.5 hours sleep on a school night, but over nine hours on a weekend when he's free to sleep as long as he wants. This has repercussions not only for learning, but for health and safety. Sleep-deprived people are at greater risk for emotional problems, depression, weight gain and even car crashes.


The researchers based their conclusions on sleep pattern studies that show that 10 year-olds tend to wake up naturally at 6:30 am, 16 year-olds at 8:00 am and 18 year-olds at 9:00 am, and allowed each group two hours between wake time and start of school. Therefore, according to them, fifth grade should start at 8:30 am and high school at either 10 or 11 am. Personally, I think two hours to get ready in the morning is probably excessive for most people unless they have a long commute to school. However, schools that have implemented these late start times have seen significant student improvements.


Even the United States Air Force Academy is testing later start times for first year students and finding that those late-starting students do better not only during the first class of the day, but in all their classes. More school districts are starting to pay attention to these results, which is very good news for students.







Kelley, P., Lockley, S., Foster, R., & Kelley, J. (2014). Synchronizing education to adolescent biology: ‘let teens sleep, start school later’ Learning, Media and Technology, 40 (2), 210-226 DOI: 10.1080/17439884.2014.942666