New scientific evidence suggests that a small percentage of people have a short sleep gene. It allows them to retain their ability to think clearly and make informed decisions while sleeping very little.

The research opposes the claims of some vocal short sleepers. These high-profile members of the so-called “sleepless elite” often brag about the competitive advantage of sleeping less than six hours per night. They preach that all of us can achieve more by sleeping less.

Donald Trump, for instance, boasts that he only needs 3 to 4 hours of nightly sleep. In one very Trump-like proclamation, he even claimed that sleep and success can’t co-exist. He once said in an interview, “How does somebody that’s sleeping 12 and 14 hours a day compete with someone that’s sleeping three or four?”

American icon Thomas Edison was an outspoken enemy of sleep. The father of the light bulb slept about 3 hours a day, dismissing sleep as a “heritage from our cave days.”

The new study identified a rare gene variant that provides a greater resistance to sleep deprivation. The gene mutation allows some people to get away with sleeping less than the rest of us.

Researchers compared 100 pairs of twins. They found that a twin with the p.Tyr362His variant of the BHLHE41 gene slept at least an hour less than his twin brother, who didn’t have the gene. This short-sleeping twin also had fewer mental errors during a 38-hour period without sleep. After sleep deprivation he required less recovery sleep than his twin brother.

The study is published in the August issue of the journal Sleep. It is only the second study of its kind to identify this type of short sleep gene.

It is clear that few people in the population have a genetic variant that enables them to sleep less. Seven to nine hours of sleep per night is still what most of us need.

Most aspiring short-sleepers are potentially sabotaging their careers by restricting their sleep. They also are risking their health in a misguided attempt to get ahead.

Self-inflicted sleep deprivation also can ruin your appearance. A 2010 study found that participants looked more tired after sleep deprivation than after eight hours of sleep. They also looked less healthy and less attractive.

Producers of a recent video confronted a group of young adults about their short-sleeping lifestyle. To drive the message home they enlisted the help of a professional makeup artist. Each subject pledged to sleep longer after seeing how sleep deprivation would cause them to age less gracefully:

Are you a short sleeper or just short on sleep? A true short sleeper functions well during the day on less than six hours of sleep. Loading up on caffeine or binge sleeping on the weekend are signs that you’re not getting enough sleep.

Regardless of what Donald Trump says, make sleep one of your top health priorities. Sleep is a necessity, not a luxury, and it’s one of the three pillars of a healthy lifestyle.