I Found the Key to the Kingdom of Sleep

It’s my foot.

Boy sleeps with his dog in a bed
Keystone View / FPG / Getty

In order to fall asleep at night, I must run a gantlet of bedtime rituals. I must be marinating in overnight-skin-care products from head to toe. One (but only one) of my legs must be hooked around the side of my covers, poised to alert me to the presence of monsters. I must be lying on my stomach, with one arm folded under my head between me and my pillow. Not only must the air in the room be frigid, but it must be blowing directly on me.

Most people will probably cop to at least one idiosyncratic sleep habit. The presence of a fan is a common one. Some people are so attached to a particular pillow that they’ll haul it through the airport. Others are dead set on having their toes dangle off the mattress. Some adults still cuddle a stuffed animal. I started taking this inventory of bedtime peculiarities after someone asked whether I could explain why her face always had to be touching her childhood blanket at night.

Requiring a particular toe positioning or pillow assortment can sound silly, but if you’re convinced you need these rituals, then their absence can affect your ability to fall asleep, disturb someone you sleep with, harm your job performance, and mess with your life. Clinical sleep disorders such as insomnia or apnea affect as many as 70 million Americans, and 60 percent of the country’s adults report experiencing sleep problems every or most nights. Bedtime eccentricities might not have an obvious connection to such widespread difficulties, but they can play a quietly pivotal role. For most people, how they came to develop the entries on their own nighttime checklist is entirely opaque, as is why completing them feels so essential.

One of the biggest factors in creating sleep rituals is comfort. “It’s about this descent into sleep and getting into a comfortable place, and you will start to replicate that night after night,” says Dianne Augelli, a sleep-medicine expert at Weill Cornell Medicine and New York–Presbyterian Hospital. People tend to return to the circumstances of sleep that have worked in the past, even if they don’t realize that’s what they’re doing and they’re not satisfying any real physical need.

Other habits might be meeting physical and psychological needs that are less obvious. “Our hands and feet will tend to warm, and our core body temperature will cool, as we’re descending into sleep,” Augelli says. “We need to have the cooling of our core body temperature to help initiate sleep.” She says that many people who have hard-and-fast rules about sticking their foot out of their covers or wearing socks to bed are trying to regulate their entire body’s temperature. The same is true for people who want a fan nearby, which has the added benefit of helping drown out intrusive noises—another enemy of sleep, even if you don’t wake fully in the night to notice them happening.

Augelli notes that the consequences of disrupting people’s deeply ingrained habits vary widely depending on the individual. For some people, simply not being able to configure their pillows according to preference can start a stressful chain reaction. “If we get frustrated or anxious about falling asleep, that actually makes us more activated and wakeful,” Augelli says. “We always want to be mindful and have healthy sleep practices and keep a nice sleep environment, but we don’t want to put too much pressure on sleep, because that can indeed backfire.”

Augelli’s explanation of the vicious cycle of sleep anxiety and sleeplessness snapped into quick focus something I’d never understood. When I’m watching a movie on my couch, I can fall asleep easily without satisfying any of my sleep rituals. Apparently that’s because when I’m in my living room, I’m not thinking about sleep or trying to achieve it. Rituals might be helpful in preparing the mind for sleep, but Augelli notes that the need to maintain them can also be stressful, especially in unfamiliar environments. Being conscious of how much you want to fall asleep is among the biggest and most common barriers to actually sleeping.

Susan Malone, a nursing professor at New York University, says that people with poor rest patterns frequently put too much effort into falling asleep. To combat that anxiety cycle, she recommends something that might sound counterintuitive: “We tell people that if you’re not asleep in 15 minutes, or if you wake up and you’re awake during the night, get out of bed,” she explains. “We try to create a very strong connection between the bed, bedroom, and sleep.” Malone also recommends against taking naps and sleeping in on weekends if you’re trying to break bad sleep habits, because letting yourself get fully and profoundly tired helps your body override expectations and rituals to wind down.

Many sleep rituals are benign, but problems can start when people’s senses of psychological and physical comfort pull them in different directions. When I gave my laundry list of environmental and position preference to Augelli, she audibly groaned. Stomach sleeping is not very good for your back, and it probably goes without saying that having one of my shoulders at maximum extension for a third of my life could create some problems down the road. My psychological preferences don’t currently cause me any discomfort, but I’m still relatively young. “As we get older, we do become more sensitive and more easily awakened by things that are not comfortable,” Malone says.

For people already in their aching prime, Malone notes, overriding old, unhealthy sleep rituals can help them avoid pain and sleep more soundly. Still, she acknowledges that changing harmful sleep behaviors can be a lot more difficult than other daily health interventions, such as drinking more water or taking a multivitamin. Even one bad night of sleep can significantly impact how a person performs at work and behaves in social situations, and Malone estimates that creating a new sleep habit takes most people anywhere from eight to 12 weeks.

Scientists still know relatively little about why people need to sleep in the first place, but the ability to do it regularly determines so much about the quality of a human’s life. If people seize on toe-dangling, pillow-arranging, or another generally controllable factor to provide a sense of calm, it’s probably because summoning sleep on demand is often so futile. “A good analogy is if you were to go surfing, you can’t try for a wave to come,” Malone says. “You just have to wait for it to come.”