One out of every three people reports struggling with insomnia.
For some, they’re unable to fall asleep, while others experience sleep maintenance insomnia, which means they can’t maintain a state of slumber.
However, these wakeful periods in the middle of the night might not be so abnormal. In looking at the history of human sleep, documented evidence shows that people would purposely divide their rest into periods. This practice is in sleep science known as biphasic or segmented sleep.
In this article, we’ll take a look at sleep history, including biphasic rest and how it may be helpful in the modern world, full of various sleep disorders.
When Was Sleeping Invented?
For as long as humans have roamed the Earth, we’ve needed sleep. As civilizations evolved, so did the way humans rested. Cultural shifts, migration, and technological advancements are considered factors in the evolution of sleep.
Much like breathing and eating, sleep is a natural function. Researchers have pointed to four theories as to why we need shuteye.
The first is Inactivity Theory, which suggests rest became a survival adaption that allowed creatures to become quiet and still during times when they’d be most vulnerable. The second theory is known as the Energy Conservation Theory. This suggests that sleep allows living beings to minimize their need for energy, especially if food sources are scarce since your metabolism slows down while you’re asleep.
Restorative Theory’s approach to slumber believes that we require rest to rejuvenate and repair our body, while Brain Plasticity Theory points to sleep’s role in brain development in babies and children.
History of Ancient Human Sleep
With historical documentation of early hunter-gatherer and agricultural societies limited, researchers have looked to present-day communities living in similar ways to assess the sleep habits of ancient civilizations.
A team of researchers from UCLA examined three traditional hunter-gather groups in Tanzania, Bolivia, and Namibia. In this sleep research, they found that the people went to sleep about 3.5 hours after sunset, challenging the idea that staying awake later may result from modern technology. The average sleep duration was 6.25 hours, with the subjects sleeping less during summer and more in winter.
Additionally, they found that the subjects rarely woke up during the night. Based on the findings in this sleep research, the researchers suggest that biphasic sleep evolved after ancient communities migrated further north toward Europe, in which the longer nights may have interrupted sleep patterns, ultimately leading to segmented rest.
1400s – 1500s
With the help of textual references, researchers such as Roger Ekirch point to evidence that segmented sleep patterns were common practice during the late Middle Ages and Renaissance. During this time period, it was considered a regular habit to have a first and second rest period during the night while experiencing a peaceful wake time in between.
Instead of feeling concerned over being awake during the middle of the night, citizens would use this time for prayer, reflection, sex, chores, reading by candlelight, and visiting friends.
References to biphasic sleep began to taper off during the late 1600s. According to a report from the BBC, this pattern initially started in the urban upper-class groups of northern Europe and eventually expanded to the majority of Western civilization over the next two centuries.
19th Century – Present Day
The Industrial Revolution was in its prime during the 19th Century. Long working days and regimented factory schedules (including two shifts) meant that people could no longer take a nap break whenever they wanted to. Instead, for efficiency, they began compressing their shuteye into a single cycle.
With the advent of publicly lit streets and electricity, urban residents further shifted away from a biphasic schedule. They also became more conscious of the passage of time and the productivity afforded during the waking state.
By the 1920s, all references to a biphasic or segmented sleep schedule had entirely ceased.
Why People Engage in Biphasic Sleep
While biphasic sleep has been largely phased out from modern society, this schedule allows for more flexibility.
Also, considering that people with sleep maintenance insomnia may rest like this naturally, it could be beneficial for them to stop trying to fight a regimented monophasic schedule.
Segmented rest is still prevalent in certain cultures, such as Mediterranean, Hispanic, and Muslim communities.
Traditional biphasic sleeping may not be conducive to most people’s schedules because it requires going to bed soon after dusk. Many work-related and family obligations require that individuals stay up later and rise at an hour that allows them to get to work on time.
While some people have enough flexibility to adhere to a routine like this, they may find that biphasic sleeping leaves them with a feeling of sleep deprivation and fatigued. In cases like this, a monophasic schedule is probably best for them.
Different Types of Biphasic Sleep
There are two types of biphasic sleep patterns. The first, commonly practiced during the 15th and 16th centuries, is when you go to sleep in the evening, wake up during the night for several hours, and fall back asleep. The second type is when you sleep at night and take a nap during the day (and is usually caused by daytime sleepiness).
Some human beings actively pursue a sleep pattern that includes more than two different sleep sessions. This is known as polyphasic sleep. Some research suggests that this type of rest pattern may help reduce the adverse effects of sleep deprivation.
Frequently Asked Questions
What did humans sleep on before beds?
Before the days of Tempur-Pedic and Casper, humans slept on makeshift sleeping surfaces like piles of straw. As society advanced, primitive mattresses were fashioned out of stuffed fabrics, and down was introduced. Bedframes came much later but have still been around since the ancient Egyptians era.
What did cavemen sleep on?
A team of archaeologists discovered a cave in South Africa that presents some significant insight into how people slept during the Stone Age. They found grass bedding mixed with layers of ash believed to date back roughly 200,000 years. The researchers estimate that the ash may have been used as a deterrent against ticks and other insects.
Is segmented sleep healthy?
The answer to this question depends on who you ask in the sleep medicine world. Some doctors suggest that this type of rest is the most natural for our biological processes, which makes it also the healthiest. Other doctors argue that in modern society, it’s destructive, not practical and can cause some sleep problems and disorders.
The time between first and second sleep could be polluted by smartphones and obligations that make falling asleep the second time a greater challenge.
Our recommendation is to consult with your physician and see if this type of schedule will work for you. Gauge how you feel and make sure you’re getting the recommended seven to nine hours of shuteye within a 24-hour period.
Sources and References:
-  “Why Do We Sleep, Anyway?”, Harvard Medical School and WGBH Educational Foundatio, December 18, 2007.
-  “Our Ancestors Probably Didn’t Get Eight Hours of Sleep a Night, Either” , UCLA Health, 2015.
-  “The Myth of the Eight-hour Sleep”, BBC, 2012.
-  “1 in 3 Adults Don’t Get Enough Sleep”, Centers for Disease Control and Prevention, February 16, 2016.
-  Mohammed A. Al-Abri, Ibtisam Al lawati, Shyam Ganguly, “Sleep Patterns and Quality in Omani Adults”, National Center for Biotechnology Information, 2020.
-  Marilyn Yamamoto, “The Effects of Polyphasic Sleep on Academic Success”, University of Hawaiʻi at Hilo, 2017.
-  Lyn Wadley, Irene Esteban, Paloma de la Peña, Marine Wojcieszak, Dominic Stratford, Sandra Lennox, et al., “Fire and Grass-bedding Construction 200 Thousand Years Ago at Border Cave, South Africa”, American Association for the Advancement of Science, 2020.