When I interviewed Richard Branson in 2016, I thought I'd get that Richard Branson: an outgoing, adventurous, "Screw it, just do it" king of the grand gesture.

Instead, he was a little shy. A little uncomfortable. Even, especially at first, a little awkward. Still a great guy. Still witty, thoughtful, and charming.

But to my surprise, clearly an introvert.

Even though research shows I shouldn't have been surprised.

According to multiple studies, there is no difference in the effectiveness of introverted and extroverted leaders in terms of overall team and company performance. (Although, as Adam Grant notes, extroverts are more effective leading employees who tend to seek guidance, direction, and motivation, and introverted leaders are more effective leading employees who tend to take initiative and work well without supervision.)

That's because extroversion and introversion have little to do with social skills. Plenty of extroverts are socially awkward. Plenty of introverts are engaging.

Context also matters; some extroverts love interacting with a group but struggle with one-on-one conversations. Some introverts are uncomfortable one-on-one but, like self-described "total introvert" Metallica guitarist Kirk Hammett, can also feel comfortable performing in front of tens of thousands of people.

More important, though, the difference lies in energy.

As Susan Cain describes in Quiet, extroverts gain energy from social interactions; introverts lose energy from interactions.

An introvert wakes up in the morning with five coins. Every social interaction they spend a coin. At the end, they are depleted.

An extrovert wakes up with no coins. Every social interaction, they gain a coin. At the end, they feel rich.

As with many things, it's not who you are.

It's what you do with who you are. 

Like Elon Musk, who claims to be an "introverted engineer."

Or Bill Gates, who says, "If you're clever, you can learn to get the benefits of being an introvert ... [going] off for a few days to think about a tough problem, read everything you can, push yourself very hard to think out on the edge of that area ... to have a company that thrives on deep thinking."

Or Apple co-founder Steve Wozniak, who says, "I don't believe anything really revolutionary has ever been invented by committee."

Again, it's what you do with who you are.

And what you believe.

These are phenomenal, phenomenal leaders who are all introverts. The one thing they have in common, whether you're extroverted or introverted, is undying belief in your cause. 

The charisma is not how much energy you have. The charisma is how much you're willing to devote to that. And if it's all of it, you have charisma. You have leadership capacity.

If you're an introvert, one of your strengths is the ability to assess, analyze, evaluate, and make considered, thoughtful decisions. So is the willingness to back your decisions -- and your goals -- with determination, effort, and persistence. 

Both of which are qualities of a great leader.

As long as you make sure you spend your "energy coins" wisely.