Chapter 4

A hundred years of scientific research reveals that kids are sleeping less than ever. But does it really matter?

HERE’S WHAT A CHILD’S BEDTIME LOOKS like to couples expecting their first baby: the nursery is softly lit, the child is sweetly sleepy, the last page of Goodnight Moon has been read. After that comes the final tuck-in, the gentle kiss and, finally, the quiet tiptoe out of the room.

So how often does this happen after the kids arrive? The answer—rounding to the closest zero—is, well, zero. Or at least that’s the way it seems. Wartime over bedtime is as fixed a part of childhood as teething and potty training, except that it goes on much, much longer and is much, much more exasperating than expecting parents know. It’s not for nothing that last year’s exquisitely titled faux children’s book Go the F--- to Sleep reached No. 1 on the Amazon.best-seller list a month before it was released. But the battle to get kids down for the night does not just drive parents to distraction; it causes them to worry. Children of all ages need a fixed amount of sleep every night, right? So what happens if your kids consistently fail to get theirs?

This is surely not the first generation of parents to fret about these things. It’s not even the first generation to believe that all the new technology surrounding—and overstimulating—their kids is making the problem worse than it’s ever been. According to a recent study from the University of South Australia, the issue has been debated for at least 100 years, and while eras may pass and the recommended hours of sleep may change, one thing remains stubbornly consistent: kids do not get as much rest as professionals think they need to be healthy mentally and physically. The question is whether the professionals are right.

The Australian study, published in the journal Pediatrics, began as a straight-ahead exercise in scientific spelunking, with investigators looking for every population-wide paper about kids and sleep duration published from the end of the 19th century through 2009. They discovered more than 200 of them—with one French study dating all the way back to 1897—and two trends were immediately evident.

First, the amount of sleep recommended for every age group has declined steadily over time, dropping an average of 0.71 minutes per year. Now, 0.71 minutes is only about 43 seconds, which does not amount to much over the course of a night. But over 112 years, that adds up to about one hour and 20 minutes—and that’s
not nothing.

At the same time, the amount of sleep that kids got kept almost perfect pace, dropping about 0.73 minutes per year. No matter how low the recommended-sleep bar gets, most children never quite clear it.

Two more constants: societal hand-wringing over children’s lack of sleep and a tendency to blame the hectic pace of modern living. As far back as the late 1800s, an editorial in the British Medical Journal attributed increasing sleeplessness to the stress and hurry of everyday life, made worse by the gaslights and trolley cars suddenly filling the streets. In 1905 one study noted that “this is a sleepless age and more and more . . . we are turning night into day.” Says Tim Olds, a professor of health and sciences at the University of South Australia and the senior author of the new study: “Throughout the 100-year period, we have been blaming whatever the new technology is: radio, TV, the Internet. Information is coming in so fast that we never wind down.”

Consistent over time, too, is the parental belief that kids need a sufficient amount of sleep in order to grow. This, it turns out, is not just a myth. Studies show that about 60% of a child’s growth hormone is secreted during sleep. “What we don’t know,” says Jodi Mindell, associate director of the Sleep Center at the Children’s Hospital of Philadelphia, “is if a child doesn’t get enough sleep, do you lose that secretion, or does it just shift to daytime?” What’s clearer—and a relatively new finding—is that getting too little sleep may have a role in obesity. One Israeli study found the effect in babies as young as 6 months. (Research on adults confirms it has that affect on grownups, too.)

SLEEP TIGHT American children, on average, sleep less than those in almost all other countries—and a full hour less than those in Australia.

So if everyone agrees on the value of sleep, why is the recommended amount always in flux? The troubling answer, according to Olds and his colleagues, is that those recommendations are for the most part subjective. “Every so often, a group of blokes get together and say, ‘What do you recommend, boys? Should we push it up to 9 hours, 15 minutes?’ ” says Olds. “It really is like that, honestly. It’s an arbitrary public-health line in the sand that people draw.”

Plenty of researchers disagree with this—and do so vehemently. Olds’s research, which he considers “quite innocuous, something of a cameo study, really,” has generated a flurry of controversy, with no fewer than 78 sleep experts and professionals deriding his scholarship as “a great disservice to children and families” in a response in Pediatrics. Others have sent him fan mail. People view sleep, he says, as “a lightning rod for their troubles.”

There’s more than just professional bickering involved here. The fact is, sleep is a notoriously tricky thing to study. Every individual’s physiology is different, and just knowing how much sleep a child gets is not the same as knowing how much that child needs. Ten hours may be too little for one 8-year-old and too much for another. And the best research tool yet discovered—asking a child, Do you feel sleepy?—lacks a certain objective rigor.

Still, Canadian research has found that as many as 68% of teens report feeling “really sleepy” in the morning, and 23% suspect their grades have suffered as a result. But both adults and kids go through cycles of high and low energy during the day, which can reflect when a person last ate, the particular activity he or she is engaged in at any given moment, and other variables. The key metric should not be how many hours of sleep you logged the night before but how many you need to perform at your peak, and there’s almost no data about that—in part because of the ethical implications of depriving subjects of sleep and then sending them to work or to school. “We’re not saying kids don’t need more sleep,” says Olds. “My hunch is, yes, they do. But we haven’t seen good evidence of that.”

None of this stops the 21st-century descendants of 19th-century scientists from issuing sleep guidelines of their own. In the U.S., the most often cited sleep recommendations are from the National Sleep Foundation in Arlington, Va. [see them at left]. What’s especially noteworthy, particularly to the bewildered parents of teenagers, who seem to be up at all hours, is that adolescents require a minimum of eight hours. In fact, kids in that age group may simply be shifting their internal clocks, going to bed in the wee hours and getting up at noon because that’s what their bodies need at that stage of development. Most teens emerge from this vampiric stage none the worse for it, though parents should try to keep things from getting out of hand. “It’s best to keep them in the proper time zone,” says Mindell.

A final wild card in all discussions of sleep duration is the way guidelines change from country to country. Australian children, for example, sleep almost a full hour per day more than American kids, who sleep less than kids in nearly all other countries. And different cultures have different tolerances for sleepy children. In Japan it’s more or less accepted that students sometimes doze off in class because they’ve stayed up late studying the night before.

The best advice for parents, as with so many things, is simply to know your kids. Observe their body clocks by noting how long they sleep on weekends and holidays when there’s no need to get out of bed for school. Track their grades as they sleep more or less. And above all, try to stay calm. They do eventually go the, er, heck to sleep. Just never as easily as Mom or Dad would like.

Why Bed-Sharing Is a Bad Idea

The latest thinking is unequivocal: don’t do it

BY ALEXANDRA SIFFERLIN

Bonding with a baby early in life is critical for his or her development, but medical experts warn that allowing infants to sleep with their parents in bed is too close for comfort.

Roughly 14% of infants in the U.S. share a bed with an adult or another child, a proportion that doubled since 1993. Parents might think that kind of snuggling strengthens a connection, but pediatric sleep experts caution that the consequences could be deadly. Topping the list of concerns is the risk of sudden infant death syndrome (SIDS), the leading cause of death from ages one month to one year.

“There are so many things that are not safe about bed-sharing,” says Jeffrey Colvin, a pediatrician at Children’s Mercy Hospital in Kansas City. “All those blankets and pillows are associated with an increased risk of SIDS, but even if you get rid of those, there is still an adult in the bed.” In a recent study, Colvin examined 8,207 infant deaths and found that the most common cause was bed-sharing.

Even if parents don’t accidentally roll on top of their child, it’s possible they will scoot too close to their baby’s face, not leaving enough breathing room or inadvertently covering the mouth or nose. “Especially for infants under three months, they simply don’t have the ability to get out of the way,” says Colvin.

In 2012 a meta-analysis of studies looking at SIDS and bed-sharing published in the Journal of Pediatrics showed that bed-sharing was associated with nearly three times the incidence of SIDS, and the risk was 10 times as high when the infant was less than three months old.

“We didn’t say you can’t bring the baby into bed for cuddles or rocking, but you shouldn’t go to bed with the child,” says Robert Carpenter of the London School of Hygiene & Tropical Medicine, who has studied the topic.

Some argue that the studies don’t properly account for where a child is sleeping, whether it’s a bed, chair or couch—the latter two are considered very dangerous places for babies to sleep. But that’s not enough to sway experts. “The data coming out doesn’t always agree, and it’s a little bit messy,” says Michael H. Goodstein from the task force on SIDS of the American Academy of Pediatrics (AAP). “But we are always looking at this issue.”

Even though sleeping recommendations have changed throughout the years—doctors used to say babies should sleep on their stomach, for instance—the risks for bed-sharing are clear-cut. “Parents have a right to approach their doctors’ advice with some skepticism,” says Colvin. “But what I tell them is that back in the 1970s and ’80s, doctors advised parents based on their gut feelings. Now our advice is based on research.”

That doesn’t mean parents need to leave baby all alone. While the AAP recommends that babies not sleep in the same bed as their parents, sleeping in the same room is just fine and actually encouraged. Rather than putting the baby in harm’s way, sleeping nearby reduces the risk for SIDS by half.