Passion is both authentic and charismatic – when it comes from a real place in the emotions. That kind of passion is expressed first, and best, through gesture and motion.  The closer you get to people, the more energy there is between you, and so the more passion.  The basics of expressing passion through gesture are simple:  someone waving her hands around and grimacing looks more passionate than someone standing still and keeping a deadpan face.

But passion can be telegraphed through quiet moments too. Just watch a great actor and feel the emotion emanating from him or her in the quiet moments.  If we’re attuned to the person, we can pick up on very subtle expressions of emotion, from the tiniest changes in posture, in gesture, and in breathing. 

We don’t fully trust people until we’ve seen them get emotional – angry, sad, ecstatic – because these moments allow us to take the measure of their values. What gets them angry, sad, or ecstatic?  That’s how we size them up. If we see someone giving a tongue-lashing to a sales clerk because the store is out of an item, we make one kind of judgment about that person. If we see someone else standing up to a bully, we make another kind of judgment.

Sincerity of emotion shows up in nonverbal conversation through, perhaps surprisingly, stillness and openness. While the strong passions – anger, joy, excitement of various kinds – can all be signaled with energetic body movements, sometimes extreme stillness can be just as effective. Think of it like the voice: the point is to establish a baseline and then vary that to exhibit the emotions.

We worked with a speaker who was telling a personal story to a large audience and revealing information that had not been public before. There was a lot of tension on his staff before the big night. We talked with the speaker about many ways that he could indicate his passion to that audience, but in the end we settled on simplicity. He stood very still and told his story very quietly. The passion came through.

That said, for most of us, when we want to telegraph passion, we need to do so with raised voice, higher pitch, more hand and arm gestures, more body movement in general – all the signs of energy and passion that we are used to recognizing.  But rather than thinking about this as a technical exercise, the better way is to focus on the passion itself.

Before you go into an important meeting, begin a high-stakes speech, or have that conversation with your teenager that you’ve been putting off, focus on the way you feel about the topic and the person or people you’re communicating with. This technique has two benefits. First, it will put you in the moment if you do it well, allowing you to connect the two conversations and appear authentic and charismatic. And second, it will occupy your mind and keep you from getting nervous.

If you think only about your nerves, your self-consciousness, and how poorly the scene is certain to go, you will almost certainly telegraph nervousness in your second conversation and undercut your own best efforts. So spend a moment outside the room or before the meeting begins feeling the excitement you have over this concept you’re about to propose, or the passion you feel for the company and where it’s headed, or the love you feel for your teenager who has to understand the importance of a curfew and personal safety.

Being passionate is ultimately about allowing yourself to fully experience the emotion. Inhabit it, revel in it, and soak it up. That way you’ll send a consistent message, not a mixed one, and you’ll come across as an authentic communicator. If the moment is right, you’ll show up charismatically, because someone who is radiating a strong emotion is fascinating, eye-catching, and lit up in a special way that we call charismatic.

Great actors have something they call the offstage beat that they use just before they go onstage. Mediocre actors just walk on and deliver their first lines. But the great ones are already inhabiting the character offstage before they go on. They figure out where the character just came from and what state of mind she was in, and they play that rather than “an actor coming onstage.” The result is a fully believable character, and one you can’t take your eyes from. You need to develop a little of the same magic, and the way to do it is to prepare, just before the communication, not only what you’re going to say but how you feel about it: strongly, fully, and with all your physical being. That, after all, is where passion originates. And that’s how you radiate passion, align the two conversations, and convince audiences large and small of your authenticity. If you do it with enough conviction, you will be charismatic.

I’ll be talking about passion, trust and charisma at the Public Words Speaker Forum 2010, this Friday and Saturday at the Kennedy School of Government on the Harvard Campus.  Please join us if you can.