Communication by gesture

Gestures are symbols made by human movement and shapes ... some, again, are cultural, and some universal, or a combination. As symbols, they need to be learned.

The only gesture I seem to have confirmation of, is this "thumb pointing through next two fingers" gesture, which apparently means 'not a chance' or 'you get nothing', when someone asks for something. It doesn't look like a very serious gesture, but I'd only use it among friends.