Natural Human Sleep Patterns

With complaints of insomnia mounting, and marketing by drug companies becoming increasingly ubiquitous, we are turning more and more to drugs like Ambien and Lunesta to give us seven or eight or more hours of uninterrupted sleep. Pharmacists in the United States filled some 42 million prescriptions for sleeping pills last year, a rise of nearly 60 percent since 2000.

Your employer wants you awake to make them money, drug companies want to sell you products to keep you sleeping or awake, and all you need is a little nap.

It is widely believed that human sleep patterns are governed by the “circadian rhythm” (the 24-hour cycle of being awake and active and then, when it becomes dark, resting and sleepy). Built into this 24-hour pattern is, however, what is known as the “ultradian rhythm” (a series of shorter cycles of activity and rest that last about 90 minutes). Dr Ramlakhan, author of Tired but Wired: How to Overcome Sleep Problems: The Essential Sleep Toolkit, believes this “ultradian rhythm” is a throwback to our hunter-gatherer years.

Segmented sleep, also known as divided sleep, bimodal sleep pattern, or interrupted sleep, is a sleep pattern where two or more periods of sleep are punctuated by a period of wakefulness. Along with a nap during the day, it appears to be the natural pattern of human sleep. Developing and maintaining such a sleep pattern may be important in managing stress.

In Western civilization before the Industrial Revolution, it was the dominant form of human sleep patterns since the beginning of time, according to A. Roger Ekirch, a historian at Virginia Tech who has researched the history of human sleep patterns.

Typically, individuals slept in two discrete phases, bridged by an intervening period of wakefulness of one to three hours, and sometimes more.



The modern assumption that consolidated sleep with no awakenings is the normal and correct way for humans to sleep may lead many people to approach their doctors with complaints of maintenance insomnia or other sleep disorders. Their concerns might best be addressed by assurance that their sleep conforms to historically natural sleep patterns.

Up until a few hundred years ago, people typically had a bimodal sleep pattern with two 4-hour sleeps per night with a waking period in between. That waking period can be an hour or more in duration.  

Since I retired, this is exactly what happens to me almost every night. I commonly wake up after two to four hours of sleep, and it often takes awhile to get back to sleep. If it takes more than an hour, I will get up and spend time on the computer, read a book or magazine, or maybe watch a little television or something, but then I begin to get drowsy and doze off again for an hour or two. 

According to Dr. Ekirch, that’s completely normal.  At least it was normal for humans for hundreds of thousand of years. Then for some reason, people decided that they should sleep right through the night. Ekirch suggests it’s related to the advent of city lighting at night which started in the late 1600s. I think an additional factor might be our increasingly busy lives and the prevalence of the ’8 to 5′ work pattern – it’s hard to fit a bimodal sleep cycle into the intervening period.    

A medical journal in 1829 even urged parents to break their children of this bimodal sleeping pattern and, by the 1920s, nobody even remembered that it was the normal way to sleep.

The keys to becoming more productive, happier, and healthier may paradoxically lie in sleeping more, resting more, and playing more. All of these behaviors are generally shunned as being lazy. But I’ve come to that stage of life where I refuse to feel guilty if people think I’m lazy. It’s a shame that “working hard”, often with no apparent productivity gains, is often deemed a desirable quality in individuals in our society. When I hear people talk about working harder and gutting it out, I’m often reminded of the aphorism by Nassim Taleb: “Only in recent history has “working hard” signaled pride rather than shame for lack of talent, finesse and, mostly, sprezzatura.”

Sprezzatura is an Italian word that expresses the ability to display “an easy facility in accomplishing difficult actions which hides the conscious effort that went into them.” What a much more elegant way to define one’s self than things like “nose to the grindstone.”