Photo by Gandee Vasan / Getty Images.

For as long as she can remember, Jenny Carter has gone to bed late and not woken up until late the following morning, sometimes even the early afternoon. Growing up, she didn’t have a bedtime, and at university she preferred to write her essays between 6pm and 10pm. She loves evenings. They’re when she feels the most creative and can concentrate the best. But that’s not when her employer or society expects her to be productive.

“Going to bed at a ‘normal’ time feels so unnatural to me,” she says. “But society just doesn’t cater for people whose sleep cycle doesn’t fit the generic 9 to 5.” She has got into trouble at work for her timekeeping, which has led to disciplinary action. “I’ve had to write off so many events, meetings and opportunities, because they were in the morning and I just knew I wouldn’t be awake.”

Carter, 27, an NHS co-ordinator, is an “extreme night owl”, one of an estimated 8.2% of the population whose natural inclination is to fall asleep well after midnight. Left to her own devices, she’d prefer to go to bed around 3am and wake up about noon.

She has struggled to organise her life in a way that suits her natural sleeping pattern. She negotiated a slightly later start time at work – 10am – but wishes she could begin at noon and finish at 8pm. Instead, she deprives herself of sleep during the week and catches up at weekends, when she often sleeps until 3pm.

But this isn’t what frustrates her most about being a night owl. “I think one of the worst things is people equating night owls and late risers with laziness,” she says. “I am just as productive, enthusiastic and organised as others, but at a different time. Feeling completely out of sync with the rest of society is the hardest thing, like you must be the one that’s wrong.”

There’s a growing body of evidence that suggests it’s society, not night owls like Carter, that is wrong. The field of chronobiology seeks to understand how individuals are driven by an internal clock – their “chronotype” – one that is set by genetics, not willpower. The term night owl is shorthand for the chronotype that drives people to go to bed later and rise later. This contrasts with morning larks, who naturally want to go to bed early and wake up early. Most people fall somewhere between the two, with an average sleep cycle running from around 11.30pm until 7.30am. People tend to change over their lifetime. They are larks in childhood, night owls as teens, and more lark-like again as they get older.

These preferences have a huge influence on health and wellbeing. Experiments show that teens with later school start times achieve better grades, while adults tend to be healthier and more productive when they are allowed to sleep when they want and to work flexibly.

So why do night owls exist? There is no single universally accepted theory, but evolutionary biologists think that communities with more variation in chronotypes may have been more likely to survive. If not everyone needs to sleep at the same time, then some members of the tribe can stand guard and protect those who are resting.

A recent study of a modern-day hunter-gatherer tribe found that during a three-week period, there were only 18 minutes during which all of the 33 tribe members were asleep simultaneously.

Another theory is that variation is simply how genetics works. Colin Espie, professor of sleep medicine at the University of Oxford, says this mirrors differences in hair, eye and skin colour, or height. “It’s a bit like any other biological characteristic. There’s a normal distribution, so there are people on both extremes – and the majority of people are neither.”

Natural night owls are fundamentally different to insomniacs or people who stay up until the early hours because of family or work circumstances. Being a night owl isn’t a problem – unless you’re trying to fit into a schedule that doesn’t suit your natural cycle.

But this isn’t always well understood. Jessica Batchelor is a medical writer who feels most productive at 11pm in the evening. “I can’t tell anyone when I went to sleep, woke up, showered, ate a meal, or took a nap without being judged,” she says. “I struggle with feelings of guilt and shame.

“We’re brainwashed to believe that early birds are happier, more successful, more disciplined and all-round better human beings than night owls. The hours when I feel most alive are considered ‘ungodly’ and likened to a vampire’s schedule. Owls like myself internalise this message, and we believe we must be lazy, depressed and irresponsible.”

Espie has treated night owls who want to adapt their sleeping patterns. He does this by asking night owls to gradually shift their sleeping pattern earlier, usually by 15 minutes or half an hour per week, through doses of bright light in the morning. This causes the brain to shut down the production of melatonin, the hormone that causes sleepiness. In the evening, night owls must make their bedrooms as dark as possible.

“It will take quite some weeks to shift the body clock, but that way you have the best chance of shifting it for a decent amount of time,” Espie says. “You’re unlikely to convert an extreme night owl to a morning person, but you can help them get to a middle ground.”

Espie’s approach is similar to that advocated by academics at three universities whose research received widespread media coverage last year. They showed that night owls can “retrain” their body clocks through lifestyle adjustments, including exercise and meals at set times, combined with light exposure.

This doesn’t necessarily mean that night owls can easily adjust. Many think that the ideal solution for night owls is to find work that better suits their natural rhythm. For some, this may be shift work, while others opt for flexible employment, such as setting up their own business or freelancing.

This is Mary McCleod’s experience. She left her role as a fashion buyer, working 9am to 5pm, to start up her own business selling natural soaps, working 11am until 3pm, then again between 8pm and 1am. “When I was going into the office for 9am I would find my mornings would be fairly unproductive and I would tend to stay late to get my ‘good’ work done, so overall I was missing out on other activities in my day,” she says. “I love working to a schedule that suits me better.”

Hannah Edwards, who runs her cake business after her children have gone to bed, agrees. “I am absent-minded and easily distracted during the day,” she says. “Staying up late to get work finished is never a chore or a challenge – when everyone else is tired I’m just getting going. It means my productivity, creativity and output levels are then incredibly high compared to others who have nothing left in the tank.”

Flexible work schedules are currently not the norm, but sleep experts believe they should be. For 15 years, Camilla Kring has run B Society, which advises companies around the world on how to implement “chronoleadership” – the idea that they should adapt their work patterns to suit the sleeping schedules of their employees, rather than the other way around.

While morning larks equally benefit from being allowed to arrive at work early and leave early, Kring feels that the battle is hardest for night owls, who experience more stigma. Many night owls say they receive sarcastic comments from colleagues about being lazy when they arrive at work later, even when they stay late to compensate.

This mentality is rooted in our agrarian past, when farm work had to begin at dawn, she says, since people who slept in were unable to provide for their families. These ingrained belief systems are evidenced through aphorisms that span cultures, such as “the early bird catches the worm”. Kring thinks that they no longer apply to the modern world: “We should say goodbye to our inner farmer – we don’t have to get up with the cows any more.”

Equally, Kring views the idea that everyone should be in the office at the same time as a hangover from the industrial revolution, when most people worked in factories. “It’s this mentality of ‘I see you therefore you’re working,’” she says. “But that’s not the case when you’re a knowledge worker. It’s more about the quality of your work than how much you’re working.”

For night owls, the expectation that they should adapt their behaviours can also be frustrating outside work. Lisa Akker, who is 60, has been a night owl her whole life and thinks the tendency runs in her family. “It’s caused problems in my marriage. My husband doesn’t understand why I can’t change my sleep times so I can be more of a lark. My cousin is always making fun of my sleeping late proclivity; she’s the quintessential illustration of the early bird getting the worm, and prizes that.”

Some night owls say that they deliberately schedule emails to send in the morning or avoid texting friends at night for fear of judgment. Akker said she recently messaged a friend at 11.19pm to ask about her coronavirus recovery. “I texted her, saying: ‘I know you’ll answer me tomorrow, but I just wanted to know how you are.’ She responded at 8am: ‘Wow, our sleep schedules are so different!’ And the purpose of saying that is? Jeez, it was only 11.19pm.”

The prevalence of this attitude is especially surprising when you consider that in society we are all becoming more nocturnal. Till Roenneberg, the circadian biologist who developed the Munich ChronoType Questionnaire, used to determine whether we are night owls or morning larks, says that because we are exposing our bodies to less natural light than before, we are shifting our body clocks later.

“The biological clock evolved to get a lot of light during the day and get none after night, because we didn’t have electrical light,” Roenneberg says. “In the past, the distribution of larks and owls was much narrower. If you couldn’t fall asleep in those days until 2am and would routinely sleep until 10am you were probably an outlier, or you were sick.”

This is why, according to Roenneberg, it’s now the norm for people to use alarm clocks. He coined the term “social jetlag” to refer to the mismatch between most people’s body clocks and the schedules imposed on them by society. “There is practically no health factor that has been looked at that does not become worse with increasing social jetlag.”

Roenneberg’s vision of an ideal society would see nobody use an alarm clock: “[People] would fall asleep when they’re tired and wake up when they have slept to the biological end.”

So if all the scientific evidence supports the idea of flexible schedules aligned with our individual sleeping patterns, why aren’t we there yet? Employers have long been hesitant to allow their employees to work flexibly and remotely, though this attitude has been undermined by the sudden shift to online working that the coronavirus pandemic has required.

Paul Kelley, an academic who has written a book on sleep, Body Clocks: The Biology of Time for Sleep, Education and Work, thinks the problem is employers’ inherent conservatism. “Let people have a choice and see what happens,” he says. “It doesn’t cost any money and it improves the working of society. The best time you can all get together is early afternoon.”

Shifting to flexible working hours as a result of the coronavirus pandemic has been a revelation for publicist Mayah Riaz. She has always known she preferred to work in the evening, but previously stopped herself from doing so because she worried about being perceived as immature or a workaholic.

“It’s proven to me I do better work in those late hours,” she says of the recent change. “There really is something about the magic of the night and stillness. I need to stop feeling like I ‘should’ wake up at 7am or 8am.”

Part of the reason for this prejudice is that sleep science is the missing piece of the public health puzzle. Our culture mistakenly associates sleeping little and rising early with virtue. It is often extolled as a habit of successful people: for instance in the fascination with Margaret Thatcher’s four-hour rest, or articles about “sleepless-elite” CEOs who start their days with a 4am jog. Yet this belies a glaring inconsistency: around eight hours of good-quality sleep is essential for better health for almost everybody.

But Professor Espie thinks the tide is turning. When he first qualified as a doctor 40 years ago, exercise, smoking and diet weren’t taken seriously by the medical profession. “No self-respecting doctor would run clinics encouraging people to lose weight or get fit,” he says. “For many years, we’ve been advocating for sleep and it’s been falling on deaf ears. But nowadays there’s a lot being written about sleep in the media and it’s coming into the public consciousness. That’s hugely important.”

As well as a need for greater awareness of the importance of sleep, there are too many myths circulating around it. Among these is the idea that there’s a simple solution to night owls’ struggles: they should cut down on caffeine, practise better sleep hygiene, be more disciplined – and even rely on medication.

For people like Jenny Carter, this lack of understanding is interfering with her ability to live life to its fullest. She has approached GPs in search of treatment, only to be told that there’s nothing wrong with her and she should just go to bed earlier.

“I don’t necessarily feel like my sleeping pattern is a problem. It’s not that I have trouble sleeping when I am asleep. It’s not that I wake up or struggle to sleep, it’s just I sleep a lot later and wake up a lot later. The idea of taking sleeping pills is weird for me when my actual sleep is fine,” she says. “The problem is more that it just doesn’t fit in with the rest of the world.”