My grandmother wrote the following of one of my uncles in a letter that she sends out to all of her grandchildren:

". . .I had a bunch of "hyper-active" kids. Joseph was, perhaps, the most hyper. He was tentaitvely diagnosed with ADD (Attention Defecit Disorder when he was 3, but I refused to allow the tests to confirm it or to put him on medication. I always thought the medication made kids stupid. At the first "open school", Joseph was by far the most active child there, among a bunch of kids who tended to be over-active. Our first head-teacher did an experiment with him one day. He read two different new stories to a group of children. During the first, Joseph was near-by, running a toy truck back and forth and looking as though he was not paying any attention to the story. During the second story, Joseph was encouraged to sit quietly and just listen to the story. The next day, Joseph was asked about each of the stories. He was able to tell the whole of the first story with all its details. He couldn't remember much about the second. It was as though when he was asked to sit quietly, he used up all his energy being quiet and had none left over to listen with. I observed the same thing at home. . ."

Interesting that others in my family have found that, too. In college I found that I got a lot more out of my courses if I allowed myself to fidget just a bit. I'd bring an array of multi-colored pens and switch back and forth between colors to take my notes. Just the action of switching and the slight distraction of focusing on colors were enough to allow me to more fully absorb whatever the subject matter was.