Why do we gesture when we speak?  And what sort of gesturing makes for better public speaking?

We mostly gesture ‘synchronously’, meaning we make the same gesture with both hands.  We typically do so as we’re saying the important words in a phrase.  So gestures help us understand what is being said.  In fact, if you take away the gestures, and only see the person you’re talking to from the neck up, as we did (for the most part) during the pandemic, we understand about 30 % less of what’s being said.  The gestures help guide us through the phrase or sentence the other person is conveying to us.  “I flew here on an airplane,” might have a gesture accompanying the words ‘flew’ and ‘airplane’ and we would understand that the person didn’t walk, drive, or take a train, but rather flew in the ordinary way.  These sorts of gestures are known as ‘highlighters’.

That’s the ordinary stuff.  A recent study (Rizzo et al., 2025) found that, in public speaking, gestures that shape or illustrate what’s being said, such as a gesture indicating a box, or an arc, or the classic three ways to do something, make the speaker appear more confident.  That’s good, because it makes us more likely as an audience to receive positively what the speaker is saying.

The study looked at reactions to over 2,000 TED talks and three kinds of gestures – illustrators, highlighters (emphasizing the important words), and random hand waving – to find that illustrators created the most positive response.  We rate the speaker higher on expertise, and we find them easier to understand.

There’s an important caveat to keep in mind as you prepare your next speech, however.  The natural flow of gesturing is not what you think – in fact, it’s quite counter-intuitive.  We start the gesture before we utter the word or phrase in question.  Only a split second before, but those several milliseconds make all the difference between someone who looks natural, and like they know what they are doing, and someone who looks stiff and, well, fake.

Try this out yourself in a safe place where you won’t damage your reputation.  Pick a simple phrase, such as the one I began with, “I flew here in an airplane,” and practice saying it, first gesturing just after you say the words ‘flew’ and ‘airplane’, and then before.  It only has to be three milliseconds before, but those three milliseconds will make the difference between communication success and abject failure.  So practice this a few times, getting the hang of initiating the gesture just before you form the words, so that the gesture and the utterance finish at the same time.  It’s going to seem a little strange until you practice it.  The best way is slow down your speaking so that you have enough time to get the gesture in on top of the important word.

Once you’ve mastered this sequence with a simple gesture, such as a wave of the hand, then you’re ready to practice it with one of the illustrators mentioned in the study.  So, you might announce your three-part solution to world hunger by bringing three fingers up to your shoulder, for example, getting the gesture going just before you say the word, ‘three’.

Master that, and you are well on the way to becoming a strong, confident public speaker.