Whether or not you know any high school students that actually get nine hours of sleep each night, that’s what federal guidelines currently prescribe.
A new Brigham Young University study found that 16-18 year olds perform better academically when they shave about two hours off that recommendation.
“We’re not talking about sleep deprivation,” says study author Eric Eide. “The data simply says that seven hours is optimal at that age.”
The new study by Eide and fellow BYU economics professor Mark Showalter is the first in a series of studies where they examine sleep and its impact on our health and education. Surprisingly, the current federal guidelines are based on studies where teens were simply told to keep sleeping until they felt satisfied.
“If you used that same approach for a guideline on how much people should eat, you would put them in a well-stocked pantry and just watch how much they ate until they felt satisfied,” Showalter said. “Somehow that doesn’t seem right.”
In the new study, the BYU researchers tried to connect sleep to a measure of performance or productivity. Analyzing data from a representative sample of 1,724 primary and secondary school students across the country, they found a strong relationship between the amount of sleep youths got and how they fared on standardized tests.
But more sleep isn’t always better. As they report in the Eastern Economics Journal, the right amount of sleep decreases with age:
- The optimal for 10-year-olds is 9 – 9.5 hours
- The optimal for 12-year-olds is 8 – 8.5 hours
- The optimal for 16-year-olds is 7 hours
“We don’t look at it just from a ‘your kid might be sleeping too much’ perspective,” Eide said. “From the other end, if a kid is only getting 5.5 hours of sleep a night because he’s overscheduled, he would perform better if he got 90 minutes more each night.”
The size of the effect on test scores depends on a number of factors, but an 80-minute shift toward the optimum is comparable to the child’s parents completing about one more year of schooling.
“Most of our students at BYU, especially those that took early-morning seminary classes in high school, are going to realize that 9 hours of sleep isn’t what the top students do,” Showalter said.
You are going to make a statement like that based on one survey that students that sleep 7 hours a day are the ones that are doing better than those who sleep 8+. Correlation does not mean causation. The data is simply a survey and information of the sleep time and performance of students. Your headline implies that they do better BECAUSE they get 7 hours of sleep. As if forcing yourself to sleep 7 hours will magically make you do better in school. There are other factors involved. This is the kind of headline that misleads readers and doesn’t do justice to the researchers.
In my high school times I usually slept 7 or less hours a night. I was always tired and got nothing done until the afternoon classes. 8+ hours a night started to be closer to what I NEEDED to function properly, less than that and I was just half-powered.
The fact that top students might not get more sleep than that might be explained with that they are top students and use their time studying, not sleeping.
Useful and interesting data, but the interpretation pushes too far, by neglecting that these are *averages* of individual optima. Each individual student has an optimum amount of sleep; some higher, some lower. The study reports the average of those numbers.
In short, parents should not be trying to push their kids toward the mean, but rather using the mean to inform their observations of their own kids, in an effort to find *that kid’s* optimum, whatever it might be.