The Australians hardwired to be up through the night
Abhinav Shrivastava is a rare natural night owl. (Supplied)
Abhinav Shrivastava's parents were early birds — academics who got up at 4am to start working.
But he took after his uncles, photojournalists who thrived in the hours the world went quiet, and routinely went to bed at 4am.
"My mother tried to make me wake up really early in the morning and do my studies … it never worked well for me," Mr Shrivastava said.
It took time for his parents to accept his clock ran differently, but the clincher came when he was 13 years old.
Abhinav Shrivastava prefers to work through the night, when most people around him are sleeping. (Supplied)
"We had an exam in the morning and I just decided 'you know what, I'll cram through the entire night and then directly go to the examination hall', and it worked quite well," the now 35-year-old recalled.
"It's one of those interesting things, when you are in your natural rhythm, you feel quite comfortable … It was liberating.
"I figured out I was quite hardwired."
University was the first time Mr Shrivastava could truly live by his natural rhythm.
"It's comfortable for me to wake up at three in the afternoon, get stuff done then start working from seven in the evening and keep going until three or five in the morning," he said.
Sleep experts estimate about 16 per cent of people are naturally inclined to stay awake until the early hours of the morning. (ABC News: Geraden Cann)
While others chased sleep, Mr Shrivastava said he thrived working in silence, free from phone calls, messages and push notifications.
The RMIT academic has tried to shift to a daylight schedule — using melatonin (a hormone that regulates the body's sleep-wake cycle) and light therapy.
"I've tried it all," Mr Shrivastava said.
He even married a sleep researcher, but still his body stubbornly craved the night.
Medically, Mr Shrivastava might be diagnosed with delayed sleep phase syndrome — a disorder where individuals sleep far later than normal.
Professor Shantha Rajaratnam says screen time may be contributing to more night owls. (Supplied: Monash University)
Shantha Rajaratnam, who heads the School of Psychological Sciences at Monash University, said Mr Shrivastava's sleep pattern was not that unusual.
Best estimates suggest roughly 16 per cent of the population sleep extremely late, nodding off between 2:30am and 7am.
Professor Rajaratnam said artificial lights and screens may be pushing more people into this category.
"We may be creating more night owls," he said.
The making of a genetic night owl
How Mr Shrivastava differs is he belongs to a group who appear hardwired to be awake through large parts of the night, and who resist treatments to adjust.
The size of this group isn't known but, in 2019, Professor Rajaratnam helped conduct a study of 116 night owls that identified biological characteristics that contributed to someone leaning toward the nocturnal.
Researchers at Monash University's sleep lab monitor a study subject. (Supplied: Monash University)
By combining sleep scheduling with melatonin for one group, while giving the other a placebo, the experiment identified a variation in one "clock gene" — the PERIOD3 gene — that predicted how well participants responded to melatonin.
Another factor was light sensitivity.
A person's internal clock is adjusted by light entering the eye.
"There are 50-fold differences in people's sensitivity to light, so some people can be shifted to an earlier time zone with less light than others," Professor Rajaratnam said.
One sleep physician estimated about one in 1,000 people are hardwired for the night. (Supplied: Monash University)
Night owls also had a longer circadian clock, and a longer "free running period", which dictated how long the body naturally stayed awake if all stimuli, including light, were removed.
"The average in healthy humans is about 24.2 hours in terms of the period length, but there are some people who are 24.5 and 24.8, and so on," Professor Rajaratnam said.
"Their clock is trying to get later and later."
Most night owls can adapt
David Cunnington has been a sleep physician for 25 years.
He estimated about one in 1,000 people were hardwired for the night.
"When people don't respond to treatment, very often it is because of other factors," he said.
"Examples of other factors are depression, trauma, ADHD, autism spectrum disorder, and stress.
"There are still people who struggle to adapt to a daytime routine without these factors, but they are less common."
In ages past, Dr Cunnington said, night owls may have manned the campfire, and society still had a role for them.
"Twenty per cent of people in Western societies work non-standard hours, so there's lots of opportunities to be working all hours, night and day," he said.
Dr David Cunnington says factors such as stress, depression and trauma may make it hard for some people to adapt to daytime routines. (Supplied)
Dr Cunnington said he had not met many he believed were hardwired for the night, but one was Rosemary Joyce, who now manages the sleep unit he works with.
Ms Joyce said she has had night owl tendencies since childhood, when she struggled to get up for school.
"I think there's some genetic component to it, but also some environmental stuff — being child number eight of a big family and being sent to bed before everyone else, possibly I had a bit of late-night FOMO."
Rosemary Joyce says she is much happier living by her natural body clock rather than trying to fit into a more common daytime schedule. (Supplied)
Her father — a farmer — was also up past midnight most nights.
In her 20s, Ms Joyce was usually the last person standing on a night out, and when she had tried early shifts, they left her exhausted and without a social life.
She has found her own niche and a natural fit managing the sleep unit.
"A lot of people who work in sleep tend to have some form of sleep disorder or another."
Sleep education lacking, expert says
SleepHealth Foundation chief executive Moira Junge said education on sleep was lacking, with 47 per cent of medical professionals having no sleep training in their curriculum.
"It has only been recognised in the last little while how important sleep is," she said.
Sleep Health Foundation chief executive Moira Junge says the majority of night owls who wish to change their sleep schedule are able to via the likes of light therapy and melatonin treatments. (Supplied)
Dr Junge said it was important to acknowledge night owls were normal.
She said many teenagers went through a stage where their sleep shifted backwards.
Abhinav Shrivastava would naturally sleep until the afternoon, but his dog Cosmo wakes him at 6am daily. (Supplied)
As society understood sleep better, Dr Junge said Australia could adopt more flexible work and school times to cater to late-risers.
While some struggled with being night owls, she said others accepted it, finding careers in casinos, shift work, or security.
For Mr Shrivastava, his internal clock is a point of pride.
While his parents accepted his night owl tendencies, he may have met a nemesis who won't — a puppy called Cosmo.
"He forces us to wake up really early," he said.
"It takes me about two coffees to actually get going."