The Idea of Needing Less Sleep
We all know someone who claims to thrive on four or five hours of sleep. They are up early, productive all day and seem to function perfectly well on what most people would consider a dangerously small amount of rest. For years, people like Margaret Thatcher, Elon Musk and various high-profile CEOs have been celebrated for their apparent ability to outperform on minimal sleep.
But is this actually possible? Can some people genuinely function well on significantly less sleep than the recommended seven to nine hours, or are they just better at pushing through the consequences? The answer lies in a fascinating genetic discovery.
The DEC2 Gene Discovery
In 2009, researchers at the University of California, San Francisco, identified a mutation in a gene called DEC2 that appears to allow certain people to function normally on just four to six hours of sleep per night. This was the first genetic evidence that some individuals are genuinely wired to need less sleep than the average person.
The research team, led by Dr Ying-Hui Fu, studied a family in which multiple members naturally slept only about six hours per night without any apparent negative consequences. When the researchers identified the specific DEC2 mutation responsible, they confirmed it in animal studies. Mice with the same mutation slept less than normal mice but showed no cognitive or health impairments.
How Rare Is the Short Sleep Gene?
Here is the important part: the short sleep gene is extremely rare. Researchers estimate that it affects less than 1% of the population, and some estimates put it as low as 1-3 people in every 100,000. This means that the vast majority of people who believe they function well on minimal sleep are almost certainly experiencing the effects of sleep deprivation without recognising them.
Since then, additional gene mutations associated with short sleep have been identified, including ADRB1 (discovered in 2019) and NPSR1. Each of these mutations appears to affect sleep regulation in slightly different ways, but all share the common outcome of allowing genuinely restorative sleep in a shorter timeframe.
The Danger of Thinking You Are a Short Sleeper
This is where the short sleep gene discussion becomes genuinely important for public health. Because the gene is so rare, the overwhelming majority of people who sleep less than seven hours are not short sleepers. They are sleep-deprived people who have adapted to functioning in a compromised state.
You Stop Noticing the Impairment
One of the most concerning findings from sleep research is that people who are chronically sleep-deprived lose the ability to accurately assess their own impairment. A landmark study from the University of Pennsylvania found that after two weeks of sleeping six hours per night, participants showed cognitive impairment equivalent to staying awake for 48 hours straight, but they rated their sleepiness as only slightly elevated.
In other words, if you have been sleeping five or six hours for years, you may genuinely believe you feel fine because you have forgotten what properly rested feels like. Your baseline has shifted, and what you consider "normal" functioning is actually a diminished state.
Health Consequences
For people without the short sleep gene, consistently sleeping less than seven hours is associated with increased risk of cardiovascular disease, type 2 diabetes, obesity, weakened immune function, depression, anxiety and cognitive decline. These risks are real and cumulative, even if you don't feel tired during the day.
"I spent years bragging about only needing five hours of sleep. Then I went through a period where I consistently slept eight hours and the difference was staggering. My mood, my memory, my patience with my kids - everything improved. I was not a short sleeper. I was just used to being tired." - David H., Wollongong
How to Know If You Have the Short Sleep Gene
True natural short sleepers share several characteristics that distinguish them from people who are simply not getting enough sleep.
They have always been this way: Natural short sleepers have needed less sleep for as long as they can remember. It is not something that developed in adulthood due to work demands or lifestyle choices.
They don't use alarms: They wake up naturally after four to six hours feeling refreshed and don't need caffeine to function.
They don't sleep in on weekends: If you regularly sleep significantly longer on weekends or holidays, you are catching up on sleep debt, which is a clear sign you are not getting enough during the week.
They don't feel tired during the day: Genuinely rested short sleepers don't experience afternoon slumps, difficulty concentrating, or the need for naps.
It runs in the family: Since the short sleep mutations are genetic, true short sleepers often have family members with the same pattern.
What This Means for You
Unless you genuinely meet all of the criteria above, the safest and healthiest assumption is that you need seven to nine hours of sleep per night. The short sleep gene is a fascinating area of genetic research, but its rarity means it is not a useful excuse for undersleeping.
If you are currently sleeping less than seven hours and want to see what a difference more sleep could make, try committing to eight hours for two to three weeks. Many people are genuinely surprised by how much better they feel, think and perform when they give their body the rest it actually needs.
"I used to think I was one of those people who just needed less sleep. After tracking my sleep and mood for a month, it became really obvious that my 'fine' on six hours was nowhere near my best on eight hours." - Sarah M., Geelong
Protect Your Sleep
The short sleep gene is real, but it is vanishingly rare. For almost everyone, adequate sleep is not optional but essential. Prioritising a consistent bedtime routine, creating a comfortable sleep environment and giving yourself permission to rest are some of the most important things you can do for your health, your mood and your ability to show up at your best each day.
