Angela Hanscom:

We quickly learned after further testing, that most of the children in the classroom had poor core strength and balance. In fact, we tested a few other classrooms and found that when compared to children from the early 1980s, only one out of twelve children had normal strength and balance. Only one! Oh my goodness, I thought to myself. These children need to move!

The problem: children are constantly in an upright position these days. It is rare to find children rolling down hills, climbing trees, and spinning in circles just for fun. Merry-go-rounds and teeter-totters are a thing of the past. Recess times have shortened due to increasing educational demands, and children rarely play outdoors due to parental fears, liability issues, and the hectic schedules of modern-day society. Lets face it: Children are not nearly moving enough, and it is really starting to become a problem.

I have never thought about this issue like this. Kids not running around enough is certainly a reasonable explanation that they don't have good enough balance, which could lead to fidgeting. Really amazing hypothesis.