Dear Wendy, There is some published information about personality traits of Parkinson's patients. One such article is The premorbid personality of patients with Parkinson's disease by Poewe et al. In Advances in Neurology vol. 53 1990. It basically discusses premorbid (ie before the onset of the illness) personality traits and has some good refs. An important aspect of those theories is for us neuropsychiatrists who try to understand the disorder in its behavioral rather than motor Sx (e.g. depression, cognitive changes etc.) In general it does appear that there is a tendency (NOT in everyone) for a more rigid uncompromising personality, but not necessarily an introverted one. How does it connect to physics? It is an interesting thought. It appears that certain disposition does channel one to certain professions. Keep on theorizing! Rami Kaminski MD Mount Sinai Medical Center