Regarding sleep, there are some deeply rooted beliefs, such as falling asleep in less than five minutes being good (spoiler: not at all), that we need to sleep eight hours (we’re probably already sleeping too much), or that sleeping straight through the night is ideal.
But here’s the thing: that last one is also a myth. Sleep science, history, and biology all point in the same direction: uninterrupted eight-hour sleep is a modern invention. Understanding and embracing this can change how we approach our nights.
Until about two centuries ago, it wasn’t normal for people to sleep straight through the night. They went to bed shortly after dusk, slept for about four hours, then woke up for a while before going back to sleep until dawn.
This process is known as biphasic sleep and is widely documented around the world. Virgil already spoke of the “hour when the first sleep begins for weary mortals” in his Aeneid, although one of the people who studied this phenomenon most is Roger Ekirch, who dedicated 16 years of research and gathered more than 500 references from all kinds of documents.
We lost biphasic sleep because of artificial light. Since the 18th century, when humanity began to rely on oil, gas, or electric lamps, the night became usable time. And as we know, light is not harmless to the brain: it inhibits melatonin production and alters our circadian rhythms by advancing them. The more light we receive before sleeping, the later we fall asleep and the less likely we are to wake up in the middle of the night.
The Industrial Revolution did the rest: rigid schedules ended up concentrating rest into a single block. What human evolution had consolidated throughout our existence, the frenetic life of production and its advances transformed forever.
What to Do When You Wake Up in the Middle of the Night
When science subjects volunteers to conditions that simulate long winter nights—without light, without clocks, in complete darkness—people spontaneously return to biphasic sleep, with a calm period of wakefulness. A 2017 study conducted in an agricultural community in Madagascar without electricity corroborated this pattern in real conditions.
Light not only regulates sleep but also affects our perception of time. Research from the Environmental Temporal Cognition Lab at Keele University shows that with low lighting, time seems to pass more slowly—an effect that intensifies in people with low mood. This explains why, for many people, winter seems endless and depressive. And why, if you wake up at 3 a.m., time seems to drag on.
If this nighttime awakening has a biological basis, the key is in how we respond to it. The standard treatment through Cognitive Behavioral Therapy for Insomnia offers concrete guidelines: if you spend more than 20 minutes without sleeping, get up and do a quiet activity with soft light, like reading, for example. And go back to bed when you feel sleepy. Also, forget the clock: checking the time triggers anxiety.
But above all, it’s important to understand something: this wakefulness doesn’t need to be an alarm signal, but rather an indication of something deeply rooted in human nature. Accepting it, instead of fighting it, is often the shortest path back to sleep.
Source: www.xataka.com.br by Victor Bianchin