As a parent of two very young children, I obsess over sleep. I read books about it, I avoid activities during the day so my kids can get it, and I long for the days when I got enough of it. According to this article in New York magazine, I would be smart to hold fast to my obsession until my kids are out of high school. Apparently, sleep matters a lot not only to little kids and their desperately fatigued parents, but to elementary, middle school, and high school kids as well.
Studies show that kids from first grade to high school get about an hour less sleep each night than they did 30 years ago. Even kindergartners have lost a half hour in the last three decades. Life is busier than it used to be and working parents want to hang out with their kids before bedtime. “Until now, we could overlook the lost hour because we never really knew its true cost to children,” the article says.
Using newly developed technological and statistical tools, sleep scientists have recently been able to isolate and measure the impact of this single lost hour. Because children’s brains are a work-in-progress until the age of 21, and because much of that work is done while a child is asleep, this lost hour appears to have an exponential impact on children that it simply doesn’t have on adults.
This is interesting stuff. I never thought much about the effects of sleep deprivation until it became a way of life for me. Now I truly understand how a loss of sleep can lead you to forget where you live or where you parked your car at the mall. So it makes sense to me that it would have a big impact on children who are more sensitive and vulnerable than adults to everything else in life.
One study conducted by researchers at Tel Aviv University found that an hour difference in sleep between fourth graders led to a performance gap of two grade levels in school, which means a slightly sleepy sixth-grader will perform in class like a fourth-grader. “A loss of one hour of sleep is equivalent to [the loss of] two years of cognitive maturation and development,” Sadeh [the lead researcher] explains.
Dr. Paul Suratt of the University of Virginia studied the impact of sleep problems on vocabulary-test scores of elementary-school students. He found a seven-point reduction in scores. Seven points, Suratt notes, is significant: “Sleep disorders can impair children’s I.Q.’s as much as lead exposure.”
Studies show the effects of sleep loss on school performance are most pronounced among high school students. Studies of thousands of high school students show that even fifteen minutes of sleep can make a difference in grades earned in school.
Using functional MRI scans, researchers say that the brains of tired children have more trouble encoding memories, making it less likely that they will recall what they just learned. In addition, fatigue makes it more difficult for children to control their impulses and more likely they will become distracted from studying.
Not all of this is the fault of parents. In some school districts, the first bell rings early in the morning. Schools that have delayed the start of the school day have seen remarkable results in their students’ achievement.
The best known of these is in Edina, Minnesota, an affluent suburb of Minneapolis, where the high school start time was changed from 7:25 a.m. to 8:30. The results were startling. In the year preceding the time change, math and verbal SAT scores for the top 10 percent of Edina’s students averaged 1288. A year later, the top 10 percent averaged 1500, an increase that couldn’t be attributed to any other variable. “Truly flabbergasting,” said Brian O’Reilly, the College Board’s executive director for SAT Program Relations, on hearing the results.
The article also talks about the potential link between obesity and sleep loss in children. “All the studies point in the same direction: On average, children who sleep less are fatter than children who sleep more,” the article says. “This isn’t just in the U.S.; scholars around the world are considering it, as they watch sleep data fall and obesity rates rise in their own countries.”
Three foreign studies showed strikingly similar results. One analyzed Japanese elementary students, one Canadian kindergarten boys, and one young boys in Australia. They all showed that kids who get less than eight hours of sleep have about a 300 percent higher rate of obesity than those who get a full ten hours of sleep. Within that two-hour window, it was a “dose-response” relationship, according to the Japanese scholars.
I have to admit, there is a part of me that’s wondering if these are causal relationships. Perhaps there were other factors that led to the drop in academic performance or in the rate of obesity? I’m not totally convinced. But it’s good to know there’s the possibility and that maintaining good sleep habits for my kids is important. I certainly won’t be the one to underestimate the power of a good night’s rest. Those were the days…