A new study has claimed that just 7 hours of sleep, instead of 9 hours recommended by federal guidelines, improves academic performance in 16-18 year olds.
The new study by Eric Eide and Mark Showalter from Brigham Young University is the first in a series of studies where they examine sleep and its impact on our health and education.
"We're not talking about sleep deprivation," Eide, the study author said.
"The data simply says that seven hours is optimal at that age," he said.
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," Mark Showalter said.
"Somehow that doesn't seem right," he said.
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.
"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," he said.
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 added.
The study has been published in the Eastern Economics Journal.