Coinciding with the beginning of the US school year, researchers at UCLA published a study last week showing a correlation between lack of sleep and poor academic performance. Some 500 high schoolers kept two-week diaries of their sleep habits, how well they understood and participated in classroom work, and their scores on assignments and tests. The ones who slept less did less well in school.
The headlines on this study—like the one at Smithsonian.com, where I first saw it—tout the results as evidence that you shouldn't stay up late cramming. But cramming usually is a special-occasion thing—something you do the night before a test—not a daily occurrence. This study is really about chronic sleep deprivation, habits and behaviors that happen over weeks and months. Along with several other studies that have come out in recent years, it helps build a persuasive case not against occasional cram sessions, but against academic routines that all-but require students to operate constantly on an abnormal sleep cycle.
For instance, military education—where students carry both heavy physical and mental loads—is highly regimented with a certain number of hours being alloted for sleep. In 2008, researchers from the Air Force Academy and the Naval Post Graduate School published results of a study that showed recruits who operated on a schedule that allowed for 6 hours of sleep did worse academically than peers who were given 8 hours. In fact, the recruits who got 8-hours of sleep scored an average of 11 percent higher on tests.
Another study, this one from 2011, found that sleep deprivation and sleep quality affected academic performance, independent of whether people were "good students" or "bad students" and independent of their personal lifestyle choices, like whether they partied a lot or not.
That doesn't mean partying isn't a factor at all. There have been a couple of studies that found correlations between alcohol consumption and not getting enough sleep. But the 2011 study suggests that lack of sleep isn't just a issue for wild and crazy drinkers and they aren't the only ones who suffer academically because of it.
Taken together, the evidence we have on the connection between sleep and academic performance suggests that the problem isn't merely an issue of student behavior, and the solution probably shouldn't be confined to lecturing kids on how they ought to be getting a full 8 hours of rest. It's also a systemic problem with the way we do education. Consider when high school starts, for instance. Studies in Minnesota (and elsewhere) have shown that simply shifting first period from 7:20 to 8:30 makes a difference not only in attendance, but also in how well students do once they get to school.
Psychology Today on delaying the start of the school day
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.