Fidgeting in ADHD improves alertness and cognitive performance.
Sarver, D.E., Rapport, M.D., Kofler, M.J., Raiker, J.S. & Friedman, L.M. (2015). Hyperactivity in Attention-Deficit/Hyperactivity Disorder: Impairing deficit or compensatory behavior? Journal of Abnormal Child Psychology. doi: 10.1007/s10802-015-0011-1