Most people need at least seven hours of sleep a night for good health. But there's a small group of people who not only subsist on less than six hours of sleep a night, but thrive on it.
Researchers are looking into whether genes play a role in determining whether a person is a "short sleeper," according to the Wall Street Journal, but they currently believe about 1 to 3 percent of the population simply don't need much sleep.
Short sleepers tend to have the same characteristics: They are energetic, outgoing, optimistic and ambitious, psychiatrist Daniel J. Buysse tells the WSJ. They tend to go to bed after midnight and wake up just a few hours later, and they do not rely on naps or caffeine to get through the day.
A human geneticist, Ying-Hui Fu at the University of California-San Francisco, is looking into whether a particular gene variation may be responsible for short-sleeping.
Another sleep scientist working on the study, University of Utah neurologist Christopher Jones, says the 20 short sleepers they have identified so far share the same characteristics: their moods tend to be upbeat, their metabolisms are higher (the people are thinner than average, even though sleep deprivation usually raises the risk of obesity, says WSJ), and they seem to have a high tolerance for physical pain and psychological setbacks.
But short sleepers for few and far between; most other Americans may be getting just the same few hours of sleep, but they're paying the price for it.
Read more: "The Sleepless Elite" [WSJ]