You’ve probably heard a speaker whose topic was fascinating … but the talk didn’t deliver because, well, because of the way it was delivered.

Here’s the problem, for people who are preparing a presentation. They spend so much time and energy on exactly what they’re going to say that they don’t pay enough attention to how they’re going to say it. They’re worried about the script and the data and the bullet points on their slides. It turns out the “how” is much more important in determining what impact you’ll have on your audience.

Researchers from Science of People studied a slew of TED talks to get an idea of what makes a talk popular. You know TED (or if you don’t you can check out www.ted.com) – 18 minute talks on just about any subject under the sun. By some of the best speakers in the country. And by some who aren’t all that.

Some TED talks go viral – they get millions of views, people pass them on to friends, and they wind up making the speaker’s career. And some TED talks languish with precious few people taking a peek.

The researchers wanted to know: What makes the difference?

They had people watch TED talks on similar topics and rate the speakers’ charisma, credibility and intelligence.

Not surprisingly, the speakers who had higher ratings were also the speakers whose talks had been viewed by more people. Higher scores for charisma, credibility and intelligence correlated strongly with the number of people who viewed a video online. The most popular TED talks rated 43% higher in charisma compared to the talks that got less attention.

This part is surprising. There was no difference in the ratings whether people watched the first few minutes of the talk on mute, or watched it with the sound on. People quickly liked the speaker … or not … not because of what they were saying, but because of how they looked and moved and gestured while they were saying it.

And they literally decided how smart the speaker was – without hearing the speaker’s words.

The implications for speakers are huge. We know that feelings are communicated mostly through non-verbals; there’s certainly other research that tells us that.

But this study of TED talks makes it so clear: charisma is communicated without words. Hand gestures are especially important (more on that next week). Facial expression plays into the impression of intelligence. And vocal variety is a major component of charisma – and credibility as well.

How often have you heard a business presentation where the speaker droned on and on and on in a monotone? You’ll see listeners checking their email or doodling or starting a conversation of their own with someone nearby.

Whether you’re speaking to attract clients … or to establish yourself as an authority in your area … or to make an impact on potential referral sources … you’ll do better if you sound natural and conversational. When you create that authentic connection with your audience, you increase the chances that they’ll want more of what you have to offer.

Other findings that might be useful as you plan your own talk:

• TED speakers got higher ratings when they wore business or business casual clothing. People in casual clothes didn’t fare as well when they were assessed for charisma, credibility and intelligence.
• Women who wore business outfits got higher ratings compared to men in business clothing.
• And speakers who wore darker colors got more favorable ratings than those who chose a lighter-colored wardrobe.

What does all this mean for you?

When you prepare a talk, spend some time thinking about what you want the audience to think, how you want them to feel, and what you hope they’ll do after they listen to you.

And consider how to use your whole body and your vocal tone to create the effect you’re going for. Don’t get so caught up in the content that you rigidly stick to a script. You’re way better off to work from bullet points and keep it conversational.

And leave yourself some time to practice the way you’re going to show up. Not the words you’re going to say, but how you’re going to stand and move and use your hands.

Focus your attention on your audience and talk to them like they’re real people, rather than reciting a bunch of facts at them.

This approach will pay off when they rate your charisma, credibility and intelligence.