Why did our ancestors sleep twice a night?

According to statistics, every third person suffers from insomnia. Night awakenings are often a cause for concern, but there is nothing wrong with it. This is what historians and psychiatrists say. Our ancestors slept twice a night and had no problems with sleep. Where did the continuous eight-hour sleep come from? Let’s find out together with somnologist Daria Lebedeva and doctor Oksana Sadykova.

How did people used to sleep?

No one doubts that it is necessary to sleep eight hours. But studies show that nature has provided a different cycle of rest and wakefulness for humans. Our ancestors divided sleep into two parts with a break of 2-3 hours at midnight. This practice is called segmented or biphasic sleep. Over time, everyone has safely forgotten about it.

In 2005, historian Roger Ekirch recalled this trick. He studied the topic of sleep segmentation for 16 years. Of course, he did not have a time machine to peek at life in the past, but he studied 500 different sources. The historian collected hundreds of documented accounts of polyphasic sleep and published them in At Day’s Close: Night in Times Past.

All the sources in his work – medical, historical and literary – point to the habit of people in pre-industrial times and before the invention of electricity to sleep intermittently. Our ancestors went to bed about two hours after dark. At about midnight they would wake up, and a few hours later they would go back to sleep – until the morning. That is, it was not typical for them to sleep like dead people. They had no fixed schedule – everything was at will. Night awakenings did not bother them at all. As Ekirch found out, ancient people spent this time with benefit: they prayed, had sex, smoked tobacco, socialized, thought and visited friends.

When did the habit of sleeping twice a night begin to disappear?

Roger Ekirch concluded that in 1920 the idea of first and second sleep disappeared. But the preconditions for a new routine can be traced back to the end of the 17th century. The fragmentation of sleep then began to be abandoned by Europeans. With the advent of electricity, there was no point in going to bed early.

Such a sleep schedule became the “norm” and during the Industrial Revolution. Then 24-hour coffee shops began to appear en masse. The surge of establishments that worked all night forced city dwellers to reconsider their habits.

In part, the tendency to sleep several times a day has survived to this day: the same afternoon nap and siesta are also considered a subspecies of biphasic sleep. Many people like to take a nap in the afternoon, but more often it is done by residents of Spain, Italy and Greece.

Daria Lebedeva

somnologist

Our body is very smart and can adapt to new conditions. Now we spend a lot of time in the office, work 12 hours a day, collect children for kindergarten or school – ancient people did not have all this. But how exactly our ancestors slept, no one knows exactly.

In general, polyphasic sleep (which is divided into several periods during the day) is more characteristic of animals than of modern man. The fact is that continuous sleep is a risk of being eaten. It is safer to sleep in short periods. In this case, it is possible to hide somewhere. Therefore, we have retained the habit of waking up in the middle of the night – that is, it is absolutely normal. We need night awakenings to roll over to the other side and check the situation around us. Evolutionarily, we can only sleep when we feel completely safe.

Is polyphasic sleep useful?

On the one hand, knowing about segmented sleep is a great way to not worry about sudden night wakings. According to a study by psychiatrist Walter Brown, if you don’t perceive night wakings as a problem, it will be much easier to cope with them. On the other hand, there is little research on the benefits of biphasic sleep. But there are a lot of opinions about it.

Daria Lebedeva

somnologist

Sleep consists of cycles, each of which lasts an hour and a half. It is logical to assume that sleeping in passages of less than an hour and a half – bad. Otherwise, sleep will be incomplete and the body will not have time to recover during this time.

The first cycle is characterized by deep sleep. In this phase we get the maximum benefit and energy. Closer to the morning comes the phase of REM sleep. During this period we dream, recover emotionally and strengthen our memory. If you do decide to sleep with segmented sleep, that is, several times a day, you should do it exactly at night. Because the sleep hormone melatonin is produced mainly in the dark.

To gain the necessary proportion of deep sleep, it is important to remember about the mode of sleep. It is desirable to sleep in pitch darkness and do not forget about the cycle of sleep and wakefulness: lie down and wake up at the same time.

Some experts suggest that segmented sleep is the most natural for humans. Others believe that for modern lifestyles, dividing sleep is impractical and can be detrimental to health. Yes, and work obliges us to fall asleep and wake up at certain hours. If you do not follow the regime, there is a risk to hang on the phone until morning, not to catch the bus, not to get to the office on time, simply do not get enough sleep and waste the day. Everything is quite ambiguous.

Oksana Davydova

doctor-somnologist, psychotherapist

In theory, the purpose of such a sleep regimen is to achieve more waking time and improve overall health. In practice, if we go against “nature”, we will get affective disorders: depression, anxiety, panic attacks. The fact is that the suprachiasmatic nucleus in the hypothalamus is responsible for the internal biological clock: it controls the production of melatonin. Therefore, sleep depends also on the time of year. In summer it is slightly shorter, because the daylight hours are longer, and in winter – vice versa. That is, the conventional norm of eight hours of sleep is an average.

In addition, our biological rhythms and internal clock are interconnected. They work synchronously with the change of day and night. This is evolutionary, so they are much stronger than our desires.

What’s the bottom line?

People used to not be distracted by electric lights, gadgets or TV shows. And so could afford to fall asleep and wake up at any time. The attributes of modern life do affect sleep. In 2017, a relevant study was published in the journal Current Biology.

Oksana Sadykova

doctor-somnologist, psychotherapist

From my practice, I can say that as soon as my patients and I normalize sleep, all disorders disappear. I believe that sleep should be full-fledged with a duration of at least 6-7 hours. Children need to sleep longer, and in old age sleep becomes shorter.

We can take something from our ancestors. For example, spend sleepless hours not on a smartphone, but on meditation or reflection. And do not forget to exercise, do not abuse caffeine and alcohol and fall asleep and wake up at the same time, even if you have nowhere to go in the morning.