Communicating in this specific way makes you much more persuasive, according to AI analysis

Effective communication isn’t just about what you say; it’s also about how you move. Skilled speakers use their hands to illustrate ideas, guide the pace, and highlight key moments.

Certain gestures, when combined with speech patterns, help people understand and remember the message.

When your hand movements reinforce your words, your audience follows along more easily and tends to find your message more convincing.

A new study from the Sauder School of Business analyzed speeches and discussions using AI and automated video analysis. 

The team learned what kinds of gestures help most and how you can use these methods in everyday situations without looking as if you’re performing a mime routine.

Gestures and hand movements

First are “illustrators” – gestures that draw the idea in the air. If a speaker says “sales climbed” and traces an upward slope, that’s an illustrator.

These gestures carry content. They sketch shape, direction, size, or sequence so the audience can see what they’re hearing.

Second are “highlighters,” which call attention to something, such as a point of emphasis or an object on a table.

Third are “unrelated movements,” which are the little fidgets that don’t carry meaning. These include fiddling with a clicker or adjusting glasses. Not every motion helps. Some simply distract.

Studying hand movements with AI

To see what happens outside a lab, the research team analyzed more than 2,000 TED Talks. They used computer vision to detect 21 landmarks on each hand in every video frame and to calculate how far the hands moved as the talk progressed.

Because cameras zoom in and out, the team normalized movement for camera distance so that a tight shot wouldn’t make small motions look large.

Then the team compared hand movement to audience reactions: how many people liked the video and how positive the comments were.

Talks with more hand movement received more positive responses, even after the team controlled for topic, speaker characteristics, voice features such as pitch and volume, facial expressions, video length, and other factors.

Movement and gestures mattered, but the team didn’t stop there.

Powers of persuasion

It’s easy to guess that “more motion is better,” so the researchers asked a sharper question: “What are those hands doing at the exact moment when particular words are spoken?”

They sliced each talk into ten‑second clips – nearly 200,000 of them – and used a multimodal AI model to label the gesture in each clip as an illustrator, a highlighter, unrelated movement, or no movement.

The model examined both the video and the transcript and achieved about 80% accuracy, with spot checks by trained human coders.

When they ran the analysis, only illustrators reliably predicted better audience response. Highlighters and unrelated movements did not increase audience response.

The team also found that illustrators were relatively rare – just a small share of all movements – so most speakers miss out on persuasive value.

“Illustrators can help make the content easier to understand because we’re delivering the same information in two modes: visual and verbal,” explains Dr. Mi Zhou, study co-author and UBC Sauder assistant professor.

“When people use illustrators, it increases viewers’ perception of the speaker’s competence.”

Matching gestures and hand movements

Your brain processes language and visuals through partly separate channels. When both carry the same meaning at the same time, comprehension gets easier.

That sense of ease – often called processing fluency – shapes how people judge quality and competence.

The study suggests a simple chain at work: when gestures make a message easier to understand, the speaker comes across as more capable, and the audience becomes more open to persuasion.

There’s nothing flashy about the process; it’s just a set of aligned signals doing exactly what they’re meant to do.

This also fits with what we know about working memory. People can juggle only so much information at once.

A clear, matching gesture can anchor an abstract phrase in something concrete, trimming the mental steps needed to make sense of it. This frees attention for the idea rather than for decoding.

Hands‑only lab tests

Observational results are useful, but experiments answer the “what if we change just this one thing?” question.

In a controlled test, an “entrepreneur” delivered the same short pitch in several ways while the researchers changed only the hands.

In the illustrator version, the speaker traced a movement that matched the words – for a skincare demo, a circular “spread it on your face” gesture. Other versions used a pointer‑style emphasis, unrelated fidgeting, or still hands.

Viewers who saw the illustrator version liked the speaker and the product more and reported greater interest in buying.

Mediation tests showed that the path ran through ease of understanding and perceived competence, just as the theory predicted. The team repeated the setup with a language app and a water filter and saw the same pattern.

When hand movement matters most

In the TED dataset, the team measured how complex the language was in each segment. If the words are simple, extra visual help adds little. If the words are dense, aligned motion should pull its weight.

That’s what the data showed: illustrators helped most when the spoken content was harder to follow. As the language became simpler, the advantage shrank.

This finding suggests a practical rule. Save your most precise gestures for the knotty parts: definitions, comparisons, ratios, timelines, and multistep procedures. When the sentence is straightforward, don’t overthink the choreography.

“One of the key takeaways for marketers is that you can use the same content, but if you pay more attention to how that content is delivered, it could have a big impact on persuasiveness,” said Dr. Zhou.

Start slow and don’t overdo it

You don’t need to constantly wave your arms and hands around for this method to be effective. Just make the important moments visible.

When you say “three steps,” hold up one, two, three. When you describe an up‑and‑down trend, trace the wave. When you talk about layers or building blocks, stack your hands in the air.

These moves give your audience a second channel that mirrors the words and lightens the mental load. The experiments show that this skill can be learned with brief practice.

Start small. Pick the two or three ideas in your talk that most need clarity. Decide what shape belongs with each – an arc for growth, a staircase for stages, a box for categories.

Rehearse the motion with the line that needs it. Keep your palms relaxed, your elbows free, and your gestures sized to the room. If a gesture doesn’t help people see the idea, skip it.

Practical uses and takeaways

The analyses of thousands of talks did not find a “too much” point where hand movement backfires. However, in real life, attention is fragile. Overly large or off‑topic gestures can pull eyes away from your words.

“Sometimes we just move our hands without a purpose. It’s a habit,” Dr. Zhou concluded. “But if you pay more attention and understand the impact, it can make a big difference.”

The safest guideline is simple: keep your hands aligned with your meaning. Let easy lines breathe. The aim is not motion for motion’s sake, the aim is clarity and making your audience, large or small, remember what you had to say.

The full study was published in the Sage Journals.

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