How Sleep Schedules Evolved Over Time

How Sleep Schedules Evolved Over Time

Posted by Lazy One on 25th May 2023

Some of us may not give much thought to sleep, especially those of us that tend to be able to sleep without difficulty. After all, sleeping is as common as breathing and eating. It's necessary and what we've always done. Every creature has a set time for sleeping and being awake, including humans.  

However, on average, it's reported that one in every three people still struggles with insomnia. For some, they may be unable to fall asleep. Others may be unable to stay asleep, with wakeful periods in the middle of the night. When we look at the history of sleep, there is documented evidence that some people would purposefully divide their rest into shorter periods. This practice is known in sleep science as biphasic or segmented sleep.

In this article, we'll look at how sleep has changed through history, including why some people seem to be able to stay Stuck In Bed while others may find biphasic rest more helpful in the modern world.


Humans need to sleep to maintain healthy bodies and minds. Many of us have natural circadian rhythms (rhythms which are physical, mental, and behavioral changes that follow a 24-hour cycle). During sleep, our bodies can release melatonin and adenosine, which triggers our sleep cycle.

While no two humans need the same amount of sleep, maintaining a stable sleep pattern provides our bodies with many health benefits.

We need sleep because it:

  • Helps us process emotions.
  • Promotes memory consolidation and learning.
  • Increases cell regeneration.
  • Boosts immune system support.


Historical resources from early hunter-gatherer and agricultural societies are limited. Therefore, scientists have turned to present-day communities living in similar ways to assess what the sleep habits of ancient humans might have been.

A team of researchers from UCLA studied three traditional hunter-gather groups. In that sleep study, they found people slept roughly 3.5 hours after sunset. The average sleep duration was 6.5 hours, with study subjects sleeping less during summer and more in winter. The researchers suggest that biphasic sleep was most likely normal during the Neolithic era as they curled up on a bed of soft grasses or materials.

Ancient civilizations, such as the Egyptians, began to worship sleep and items such as homes with beds to sleep in.


With the assistance of many textual and historical documents, from engravings to hand-written, we know that humans slept in two phases during the Middle Ages. A book published by historian Roger Ekirch of Virginia Tech, called At Day's Close: Night in Times Past (1), presents more than 500 references to a segmented sleeping pattern. Many of these references describe a first sleep that began roughly two hours after sunset, followed by a waking period of an hour or two, and then humans falling asleep for a second time.

While awake for an hour or two at night, references described people as very active. Some would get up and visit the toilet, chit-chat with family, and even see the neighbors, while others remained in bed reading, writing, or praying.

During the Middle Ages, it was considered the norm for a whole family to sleep in one big bed to conserve body heat. Bedframes and mattresses were being developed and growing more ornate over time.

Ekirch, the author, found that references to this sleep pattern began to disappear from any textual records during the late 17th century. By the 1920s, the idea of a first and second sleep had been entirely forgotten from the social consciousness.


The 19th century was the height of the Industrial Revolution. With the invention of electric lights, long working days, and regimented factory schedules, it was no longer possible to take a nap break whenever needed. Sleep became compressed into a single cycle. Many began working after sundown thanks to electric lights illuminating the streets and buildings. In contrast, others could enjoy evening activities such as reading without straining eyes. Transitioning family members to separate bedrooms also became the usual sleeping arrangement.

The 19th century was when bedsprings were invented. During the latter part of the 19th century, waterbeds and Murphy beds were prevalent in many homes. By the end of the 20th century, memory foam was invented and eventually became affordable for everyone. Today, sleep has become monophasic as we often remain awake without napping during the day and sleep for about 8 hours at night.


Unfortunately, scientists need additional research on whether attempting to return to our ancestor's habits of biphasic sleep is better, worse, or about the same as monophasic sleep.

Research suggests that taking midday naps may be linked to improved cognitive performance. Short naps of 15 minutes or less may reduce sleepiness and help mental clarity. While napping 30 minutes can result in the same benefits lasting longer, many reports say that humans experience a period of sleep inertia—that initial grogginess many feel after waking up from a longer nap.


  • Biphasic sleep may allow for more flexibility in a schedule.
  • Many with insomnia or sleep maintenance issues may already rest like this. There may be a sizeable mental benefit for them to stop trying to fight a regimented monophasic nighttime sleep schedule.
  • Segmented rest is still practiced in certain cultures, such as Mediterranean, Hispanic, and Muslim communities.


  • As no two humans are alike, what works for one person may not work for another. Biphasic sleep usually requires us to sleep soon after the sun goes down. Trying to sleep as we used to in two parts may not be the best choice for your schedule. Many work-related and family tasks need people to stay up later or rise earlier to get to work or start their daily routine on time.
  • While some may have the schedule flexibility to try biphasic sleeping, they might soon realize that this routine leaves them feeling more sleep-deprived than refreshed.
  • Chronic sleep deprivation can increase the risk for serious health problems. If someone experiences sleep deprivation and fatigue trying biphasic sleep, it is probably best they stick with a monophasic sleep schedule.

Should you attempt segmented sleep? The best answers to that question depend on what your health provider tells you. Talking to your doctor before radically changing your sleep schedule can provide you with additional recommendations and advice that may help improve your sleep quality and daytime energy levels.

Regardless of when you sleep, one way to help yourself rest better is by practicing good sleep hygiene, the habits and practices you have around sleep, such as:

  • Be consistent with what time you go to bed.
  • Keep your bedroom dark, quiet and cool.
  • Don't use your bed for work, watching movies, etc. Use your bed for sleeping only.
  • Limit caffeine intake a few hours before bed.
  • Put your phone, tablet, or laptop away 30 to 60 minutes before sleep.
  • Make a calming bedtime routine at night to get ready for sleep.

LazyOne is all about helping you drift off to Fa-La-La-Land. We hope you've enjoyed learning about how sleep has changed through history.