"Author Vanessa Edwards and her team watched thousands of hours of TED Talks and noticed something surprising: The least popular TED Talkers used an average of 272 hand gestures during their 18-minute presentations, while the most popular used an average of 465 hand gestures in the same amount of time. As she noted on her blog, that’s almost double."
"Gesturing properly can add tremendous impact to your speech. After all, your audience is doing more than listening to your words when you’re giving a presentation. They’re looking out for your body language, expressions, tone of voice, and, yes, your hand gestures. But there are also other, less conspicuous reasons why incorporating gestures can make your talk more effective and compelling. Here are a few of them."