If this helps your analysis... If I stop selecting text, I will start to play around with things on my desk. I am not overly caffeinated or full of sugar, and my legs are at rest. It just feels "natural" to be doing something with my hands all day. But this is just my own analysis.
That's what I suspected. For those of us who work with computers for most of our waking hours, our bodies get use to focusing on what we are clicking on. Thanks for your feedback.