Though it would make newborn parenting a lot easier -- and infinitely more enjoyable -- if babies slept overnight from the get-go, everyone actually starts out as polyphasic sleepers.
The brains of babies aren't fully developed and they need to eat frequently, so they spend the first few months sleeping multiple times a day. As the newborn brain develops, so does what Dr. Nate Watson, M.D. M.S., co-director of the University of Washington Medicine Sleep Center and sleep medicine specialist, calls "sleep architecture." This includes circadian rhythm -- or the development of a body clock -- cues from light/dark cycles and the secretion of melatonin, a hormone that regulates sleep patterns. All of these things help babies become biphasic sleepers, or those who do the majority of their sleeping overnight, with one nap during the day, and eventually monophasic sleepers. But in the beginning, it's a big blur of diapers, feedings, days and nights, and parents often adjust their sleep schedules accordingly.
But that's a temporary situation. There are no hard-and-fast numbers on the amount of true, full-time polyphasic sleepers (or polysleepers) in the U.S., but, according to Dr. Russell Rosenberg, chairman of the National Sleep Foundation, there are approximately 6 million night-shift workers who most likely sleep on a biphasic schedule, though some may nap frequently instead.
And they're not the only ones. You know how it is: Shortly after lunchtime, you get that sleepy feeling, no matter if you had a small salad or a triple stack burger separated by layers of bacon. In the medical community, they call that a dip in the circadian alerting signal, and in many countries in Europe, Southeast Asia, Central and South America, they call it time for a nap.
"Naps make a lot of sense from a physiological standpoint," Rosenberg says. "There's a drop in the core body temperature and a period of reduced alertness. Some cultures embrace it, but in the U.S. most people just get a cup of coffee and push through it."
If catching 40 winks relaxes and recharges the body, what's wrong with adopting a polyphasic sleep schedule? Wake up and smell the answers.