A Harvard psychologist says there's a personality trait that's just as important as charisma and is easier to develop

Some people are naturally more charismatic than others.

Bill Clinton, Oprah Winfrey, and Martin Luther King, Jr. had the ability to captivate and inspire their audiences the way few other leaders could.

Yet Harvard psychologist Amy Cuddy says there's a personality trait that's just as important as charisma - and it's considerably easier to develop.

That trait is what she calls "presence," and it's the subject of her new book by the same name. "Presence," as Cuddy defines it, is about being attuned to and able to express your full potential - whether in an important presentation or a conversation with your boss.

During a recent talk at the 92Y in New York City, Cuddy explained the difference between charisma and presence, and why presence isn't something that only certain people are born with:

Charisma seems to be more about the intoxicating quality that you have on other people, as opposed to presence, which is more about the self in relation to others, and how you feel you represented yourself in a situation, and how you were able to engage. So it's less about how others see you and more about how you see yourself.

Cuddy writes that one way to become present is through "power posing," in which you adopt the body language of powerful people so that you feel and act more confident. (Ideally, you'd do this in private, for example a few minutes before you head into a job interview.)

You can also practice self-affirmation, in which you write down your core values and why they're meaningful to you. Hopefully, both these exercises will help you feel more confident in challenging situations.

On the other hand, psychologists who study charisma say it's largely about behaviors like showing more expression in your face and using words that people can relate to.

Ultimately, both charisma and presence have a similar end result: making a positive impression on other people.

"I want people to be able to influence themselves," Cuddy said. "We convince ourselves, and that allows us to convince others."