Scientists have identified a small group of people called the 'sleepless elite'. These group of people rather being tired, bad-tempered, under-achievers, they are an energetic, outgoing and optimistic group who can happily and healthily get by on just four or five hours of shut-eye a night.
They also tend to be slim, able to hold down two jobs at the same time, and breeze through their extra-long days without needing caffeine pick-me-ups or catnaps.
American scientists who studied an extended family in California focused on a mother and daughter who appeared perfectly healthy despite their shared lifelong habit of getting up early in the morning, having gone to bed close to midnight.
A DNA test showed they had a tiny mutation in a gene called hDEC2 - but it was missing in other family members who slept normally.
When mice were genetically engineered to have the mutation, they too struggled to sleep.
Working out how the gene cuts sleep without any obvious impact on health could help in the design of drugs that give us all a few extra hours in our day.
The bad news is that while many people get by on a few hours' sleep a night, just 1 to 3 people in 100 qualifies as a member of the sleepless elite. Everyone else is simply sleep deprived.