Biphasic Sleep: A Historical Perspective on Insomnia

BY ANNIE LARSON Published in Pathways Magazine, Fall 2026, page 22.

Imagine a time when waking up in the middle of the night wasn’t a sign of insomnia, but rather a natural part of how humans were meant to sleep. The concept of segmented sleep challenges the modern notion of uninterrupted, consolidated sleep often idealized in today's fast-paced society. With the end of Daylight Savings time on November 1st this year, we will gain sleep added by turning the clock back an hour. While the idea of gaining an extra hour of sleep may sound appealing, it raises interesting questions about our sleep patterns and what historically constitutes a healthy amount of rest and what borders on insomnia.

Biphasic sleep consisted of two separate phases of rest during the night, known as "first sleep" and "second sleep." It was typical for people to go to bed shortly after sunset for the first sleep, aligning with the natural rhythms of the earth's day and night cycles. First sleep usually lasted several hours. As the night went on, individuals would often wake up for a short period, typically ranging from 30 minutes to a couple of hours. This waking time was not met with worry or stress; rather, it was seen as a chance for quiet reflection in the calm of the night. Second sleep would then begin and continue until dawn.

With the advent of electric lighting and the demands of contemporary life, the natural inclination to wake during the night has been largely suppressed. Instead, individuals strive for a continuous block of sleep, often leading to frustration and the mislabeling of natural waking as a sleep disorder.

The biphasic sleep phenomenon has historical roots, as it was once common before the Industrial Revolution. Research shows that humans often experience sleep in multiple phases, including light sleep, deep sleep, and REM (Rapid Eye Movement) sleep. It is entirely possible some people may find themselves waking mid-evening, only to return to sleep a few hours later.

The Sleep Debate: Experts Weigh In

There is an ongoing debate among sleep experts about the necessary amount of sleep for every individual. According to the US Centers for Disease Control and Prevention, adults need more than seven hours of sleep a night, but more than a third of American adults are not getting enough sleep on a regular basis. Many other studies suggest the ideal amount of sleep can vary significantly from person to person. Some individuals may thrive on just six hours of sleep, while others may require nine or even ten hours to feel fully rested. Furthermore, the concept of sleep itself is not as straightforward as simply counting the hours spent in bed.

The practice of sleeping through the night did not take hold until just a few hundred years ago, according to historian A. Roger Ekirch, a professor at Virginia Tech University. His research shows this change was influenced by the advent of electric lighting and the Industrial Revolution, which promoted the capitalist idea that sleep was unproductive, and time could be better spent working.

The work of Ekirch, and other historians, anthropologists, and sleep experts, is helping sleep scientists gain fresh perspective on what constitutes a good night’s sleep. It also offers new ways to cope with and think about sleep problems like insomnia.

"There is value in knowing about this prior biphasic pattern of sleep in the Western world," said Ekirch. He believes people today who suffer from “middle-of-the-night insomnia” (a common sleep disorder in most industrialized countries) are in fact experiencing a powerful remnant of this earlier pattern of sleep.

While studying nocturnal life in preindustrial Europe and America, Ekirch found evidence many people used to sleep in biphasic stages. The waking interval was practical, allowing people to tend to fires, pray, write, and check on animals. He and other researchers believe this midnight quietness broke up long winter nights, made time seem shorter, and may have aided emotional regulation by allowing the mind to wander without the pressures of daytime obligations. When sleep scientist Thomas Wehr put volunteers in long winter darkness in the 1990s, their bodies did the same thing: two sleeps, with a calm, reflective interval in between. Biology, it seems, remembers what culture forgets.

The demise of the second sleep was brought on initially by the use of oil, followed by gas, and eventually electric lighting that enabled people to remain awake longer. This postponed the start of sleep and consolidated rest into a single period. The necessity for factory work to adhere to fixed schedules, along with the advent of the light bulb, made a single, extended sleep cycle more feasible and widely accepted, supplanting the pre-industrial biphasic pattern. The Industrial Revolution completed this transition by valuing punctual, continuous workers and establishing the eight-hour night as the norm. This shift, combined with modern distractions, has contributed to decreased total sleep duration and sleep-related health issues.

Questioning the Sleep Science

Rethinking insomnia, Russell Foster, a professor of circadian neuroscience at the University of Oxford, said Ekirch’s findings on biphasic sleep are not without controversy. Experiments in sleep labs have shown that when humans are given the opportunity to sleep longer, their sleep can become biphasic or even polyphasic, replicating what Ekirch found in historical records.

However, Foster, who is also the director of the Sir Jules Thorn Sleep and Circadian Neuroscience Institute at Oxford, doubted it was a sleep pattern that would happen for everybody. "Nobody should impose a regime of segmented sleep on themselves, particularly if it resulted in a reduction of total sleep time," he added. What was clear to Foster was that interrupted sleep was perceived as less of a problem in the past than that of modern expectations about what constitutes a good night’s sleep. Waking at night need not mean the end of sleep.

One example he cited was that more people woke up at night during lockdowns during the Covid-19 pandemic. “They’ll get terribly anxious and worried about waking up in the middle of night, because that’s not what they normally experience,” said Foster, who is also the author of “Life Time: The New Science of the Body Clock, and How It Can Revolutionize Your Sleep and Health,” published in May 2022. More likely, what had happened was people’s sleep episodes — how much time they have available for sleep — had expanded and were not constricted by an alarm clock going off. “It’s a throwback to a time when we genuinely got more sleep,” he said.

The corollary of this is anything preindustrial is considered the golden age of sleep. Not so says Sasha Handley, a professor of history at The University of Manchester in the United Kingdom. She studies how families slept in Britain, Ireland and England’s American colonies between 1500 and 1750. Handley's research suggests sleep was a topic people worried about. Doctors’ manuals and references from the period list hundreds of recipes for sleep including “cutting a pigeon in half and sticking each half to each side of your head.”

Brigitte Steger, a senior lecturer in Japanese studies at the University of Cambridge in the UK also countered saying, “There is no such thing as natural sleep.” She writes about the cultural history of sleep, and did not find any references to biphasic sleep in her research of sleep habits in Japan. “Sleep has always been cultural, social and ideological,” said Steger.

Before the era of alarms, smartphones, and the concept of an eight-hour sleep, the night was naturally divided into two segments. People would go to bed early, awake around midnight in a period of quiet, and then return to a second sleep until dawn. This pattern was normal, not unusual or unhealthy. References to “first sleep" appear in court records, diaries, letters, and even in the works of Homer and Virgil, indicating it was widely known — nighttime has a middle.

Even now, as we enjoy an additional hour of sleep with the transition to Standard Time, imagine a period when waking up in the middle of the night wasn't a concern but a normal aspect of human life. We might reevaluate our contemporary sleep habits. So, when you wake up at midnight and wonder if you have insomnia, you may be historically sleep typical. Consider the possibility that your body has not yet adjusted to the post Industrial Revolution sleep contract.

Annie Larson, a psychic medium, is a sought-after speaker, reader, and Reiki Master Teacher  who has been featured in TV, radio, podcasts, magazines, and newspapers, including The Washington Post.  She meets clients in-person in her office in Sterling, Virginia, via phone, and online. MediumAnnieLarson.com