You know radio is a great thing. Communicating by voice alone has its drawbacks, though.For example, I can’t use hand gestures to clarify what I mean. And, as it turns out, that makes a big difference. Researchers at the University of Otago in New Zealand wanted to know how much a relevant hand gesture helps to communicate an idea. They had volunteers watch video clips of a woman saying different phrases, such as “the square box,” or “peel the banana.”