Sleep patterns have evolved over time, and the way we sleep today is vastly different from how our ancestors slept. In the past, a continuous eight-hour snooze was not the norm. Instead, people typically slept in two shifts each night, known as “first sleep” and “second sleep.”
During this period, families would go to bed early, then wake around midnight for an hour or more before returning to sleep until dawn. This two-shift sleep pattern was common across different cultures and regions, as historical records from Europe, Africa, Asia, and beyond indicate.
The midnight wakefulness was not considered dead time; instead, it was a time for various activities. Some people would tend to chores like stirring the fire or checking on animals, while others would pray, contemplate dreams, read, write, or socialize quietly with family or neighbors. Many couples even used this time for intimacy.
However, the second sleep gradually disappeared over the past two centuries due to societal changes, such as the introduction of artificial lighting. With the advent of oil lamps, gas lighting, and eventually electric light, people started staying up later into the evening under artificial light, shifting towards a single block of uninterrupted rest.
The Industrial Revolution further solidified the idea of eight hours of uninterrupted sleep, replacing the centuries-old rhythm of two sleeps. Today, our internal clocks are influenced by bright light at night, disrupting our natural sleep patterns and making it less likely for us to wake in the middle of the night.
In winter, when natural light cues fade, our sense of time can become distorted. Without the regular daily schedule and exposure to morning light, our circadian rhythms can be thrown off, leading to difficulties in time perception and mood regulation.
Insomnia, characterized by brief awakenings during the night, is a common issue for many people. Cognitive behavioural therapy for insomnia (CBT-I) advises individuals to leave bed after about 20 minutes of wakefulness, engage in a quiet activity, and return to bed when sleepy. Covering the clock and letting go of time measurement can also help alleviate sleep struggles.
Understanding the historical context of sleep patterns and how light influences our internal clocks can provide a new perspective on insomnia. By accepting wakefulness calmly and recognizing how our minds perceive time, we can improve our chances of restful sleep.
