The light bulb changed everything. Before it came, when the only practical sources of artificial light were candles & lamps, people did not often use candles to stay awake at night. These sources of artificial light costed a lot more per lumen hour. They were not always used. They were used only when artificial light was totally necessary. Normally, as the sun went down, people preferred sleeping. As bulbs came, they transformed the way we slept. Or, so argued the historian A. Roger Ekirch.
In his detailed published anthropological work – At Day’s Close: Night in Times Past – he mentions that the eight-hour single block of sleep is a recent change in our sleeping schedule. For many many years more than we’ve slept for eight hours in the night, our ancestors had practised a very different kind of sleep schedule which became the natural way of sleeping for humans. It was a segmented sleep.
The schedule went like this…
When the sun went down, there was more or less no artificial source of light. Due to this, our ancestors could do nothing useful. Bored with inactivity, they slept. Then somewhere in the mid-night, they woke up. For an hour or so, they remained awake and went back to sleep again till the morning.
The time for which these people remained awake, was probably the most relaxing and most calm time of their lives. Due to increased levels of pituitary hormone prolactin, people felt a lot at peace during this hour. During this time, people liked involving themselves in some kind of activity. Some preferred reading, others wrote. Some smoked, others visited their friends. And so on… The point is, people found themselves replenished during this time. It was apparently blissful.
This pattern of sleep became a natural way for us humans. Turns out, the eight-hour block of sleep is not the way we always used to sleep!
This sleep pattern has been observed to come back to today’s humans when they were completely deprived of any artificial light. This can be seen in the famous experiments of a psychiatrist, Thomas Wehr.
That waking hour of bliss – a fact of life before the industrial revolution came – was probably a period which I feel, needs to come back to cure the modern world’s rising anxiety, stress, depression, alcoholism and drug abuse.
Some scientists believe that if you give your bodies a chance, they’d go back to a segmented sleep pattern. This is also bolstered by Wehr’s experiments. While others prescribe you sleeping pills if you tell them you wake up at night for an hour or so.
Just for the record, I’m writing this at 2:30 AM. I just woke up, and I’m off to sleep again.
[Mastering Biphasic sleep] A detailed blogpost on the experience by Jayson Feltner…