As difficult as it may be to diagnose personality disorders or other neuropsychiatric peculiarities by one's online behaviour, such conclusions are all too often very, very obvious.

Add to that ADHD and Asperger's syndrome, and you'll probably cover most of the relevant cases.

By the way, there might be several case studies hidden in Wikipedia's user and talk pages, RFAR, this list, and private emails. What would be even more interesting were some sort of comprehensive and qualified analysis.

Kosebamse

There are significant privacy problems. We frequently don't know who a user is, nor is there any way of finding out. I suppose a researcher could contact users and ask them to participate in a study, but the sample would not be representative.

Fred