From political leaders like Bill Clinton (in his heyday, at least) and Margaret Thatcher to business legends like Herb Kelleher and Jack Dorsey, there's no shortage of stories of leaders who claim to get by on next to no sleep. Should you follow their lead, inspiring your followers with heroic feats of business endurance?

Probably not, suggests a new study. Not only does dragging yourself around on minimal sleep feel awful, it also apparently makes you a less inspiring leader.

Sleeplessness kills your charisma

To test how lack of sleep affects key leadership skills like persuasion and charm, a team of researchers led by University of Washington management professor Christopher Barnes asked 88 business school students to prepare a commencement speech designed to inspire listeners. Half of this group then gave their speech following a restless night (they were asked to complete a survey every hour) and half while they were adequately rested.

How did a panel of expert evaluators (as well as the students themselves) rate their performances? The results clearly show that sleeplessness is a charisma killer.

"The judges didn't know who the students were, nor whether they were in the sleep deprived condition or not, but nonetheless they consistently rated the tired orators as less charismatic," reports the British Psychological Society Research Digest blog.

Why does being tired rob you of your ability to charm and inspire? Apparently, sleep deprivation makes it harder to control your emotional displays and thus to connect effectively with others. That's probably not hugely surprising when you think about it, but nonetheless in a world that glorifies long hours, these findings are worth trumpeting far and wide.

"This is important because many leaders are sleep deprived most of the time," Barnes wrote of the findings. "Moreover, leaders often create sleep depriving conditions for the people they lead, such as requiring them to check their smartphones late at night. Thus, many leaders are sabotaging their own ability to effectively lead their teams. The bottom line is this: If you want to inspire, you and the people you lead all need to do your best to get a good night of sleep."

Very few exceptions

But wait, you might reply, I'm the exception to the rule. I can miraculously get by on just a few hours of sleep a night. If that's what you're thinking, science says you're probably kidding yourself. Only a miniscule percentage of people--one to three percent--can actually function well on less than the recommended levels of sleep. Chances are extremely good you're not one of them.