"When people talk, they often gesture with their hands. Even when their conversational partners cannot see them, people still gesture – when talking on the telephone, for example, or when blind people talk to each other. Young children gesture when they are trying to learn or explain a task or a concept.
These hand gestures not only communicate a message to the listener, but also reflect the thoughts of the person who is gesturing. But, while gestures may reflect an individual’s thoughts or knowledge, we still don’t know exactly why people gesture. Nor do we know why some people gesture more frequently than others."