I admit it: I'm a leg-bouncer. My wife will often elbow me during a movie to make me stop; it's distracting, she says. It's also semi-involuntary, and unless my bouncing knee is directly in your line of sight (or juddering the couch you happen to be sitting on with me) it seems like a victimless crime. I actually have video proof that I do this: Lisa Yee, a friend of mine, came to a reading/signing event I had in Los Angeles a week ago and brought her video camera -- but instead of videotaping my face (with, you know, words coming out of it), she taped my leg.
It's not just my leg: I also fidget with my hands (though not quite as much), spinning my wedding ring, twirling pens in my hand, drumming on the edges of flat surfaces. I have to think the leg and the hand behavior are connected. So why do I do it?
There was a study done in England a few years ago which found that children who fidget in class learn more quickly than children who don't. My theory is that it's a bit like listening to music to help you concentrate; I don't do it when I'm bored and nothing's going on. The amount of coffee I may or may not have been drinking has nothing to do with it. I fidget when I'm working on something. Fidgeting and listening to music help me narrow my focus.
What's your experience? Do you fidget or bounce your leg? Does it help or hinder you when working?