It's that intangible quality that separates enigmatic leaders from just so-so speakers; that je ne sais quoi quality that makes people cling on your every word.

It's charisma.

And those who truly have it often find that others are naturally attracted to their charm and personality.

It's tough to define charisma, but we generally know when we encounter a charismatic person. The sun seems to shine brighter on them--their fortune and luck seems greater, and things just come easier to them. They're more likeable and popular. People want to be around them.

Some of the greatest leaders of our time were incredibly charismatic--think JFK, Martin Luther King, or even Mother Theresa.

If you weren't blessed with charisma, all is not lost. According to new research from William von Hippel of the University of Queensland, people who are "quick thinkers" and able to answer questions faster than others are perceived to be more charismatic--even if they don't have a higher IQ, greater depth of knowledge or better personality.

Is it possible you could train your way to a more charismatic leadership style and personality, by working on your ability to think on your feet?

In a recent interview with Harvard Business Review, Professor von Hippel noted that although the results of his study didn't necessarily surprise him, he did learn that mental speed didn't seem to correlate to social skills overall--only to charisma.

"I think we all sense that charismatic people tend to be quick on their feet. They say things that you find compelling but that you don't expect. They come back with an entertaining answer or a surprising association, and you never quite know what will happen next. They're interesting. It's sort of like humor. You say something, and then I make a joke that connects it to an idea you hadn't thought of. If I can do that quickly, it makes all the difference," von Hippel told HBR.

Developing Charismatic Traits

The difference between quick thinkers and those who were identified as not as able to think on their feet seems relatively small: 400 milliseconds versus 900 milliseconds to answer a question. In actual conversation, though, a pause of that length can convey all kinds of unsaid messages--and not always the intended ones, either. People might perceive the pause before a response as uncertainty or worse, judgment.

Interestingly, von Hippel pointed out that it didn't matter whether people answered correctly or not--only that they answered quickly. Thinking fast was actually a greater indicator of charisma than IQ, in this way.

In this talk for the  Stanford Technology Ventures Program, author Olivia Fox Cabane shares her incredible insights on building charisma. You might think it's something some are just blessed with, but Cabane shares a story here that shows just how easy it is for someone who's learned charisma to turn it on and off.

Marilyn Monroe demonstrated how easily one can modify his or her behavior to be charismatic when she took a photographer into Grand Central Station in New York on a busy day, riding all the way to the next station without any attention coming her way. Cabane explains,

"What Marilyn wanted to show was that just by deciding to, she could either be glamorous Miss Monroe or plain Norma Jean Baker (her real name). On the subway, she was Norma Jean, but when she resurfaced on to the busy New York sidewalks, she decided to turn into Marilyn. So she looked around and she teasingly asked the photographer, 'So, do you want to see her? The Marilyn?' And then, he said, there were no grand gestures, she just fluffed up her hair and struck a pose. And yet, with this simple shift, she suddenly became magnetic. An aura of magic seemed to ripple out from her and everything stopped."

Charismatic Leadership Doesn't Mean Being Smartest or Most Likeable

So you want to be a Marilyn?

Regardless of how you personally define charisma, you can improve yours and use it to your advantage.

"From my perspective, you can be charismatic--but also an asshole. For example, Donald Trump is almost entirely devoid of social grace, but he's charismatic. People find him fascinating; they don't know what he's going to say next," von Hippel said. "Jeb Bush, in contrast, is a snoozer. You not only know what he's going to say but also know it's not going to be very interesting. But I'd bet he's a lot more pleasant at a dinner party or across a negotiation table."

Instead, work on developing your positive personality traits and just as importantly, sharpening your mental skills.