When reading your post Jon, it leaves one with the impression that ....of course they would have to be "not normal"...because, well, after all normal people don't have the skills!
I didn't get that impression, but more to the point, I hope I didn't give that impression too.
What do we call people who play chess in their spare time? Nerds.
Speaking as a former King Nerd when I was in high school, those chess playing cats aren't generally very normal...and that's part of why I liked them so much.
I don't think "normal" is the issue so much as what causes anti-social behavior.
While it's certainly conjecture, I think there's a validity to the idea that a person like Sokaku Takeda, who experienced some of the most base aspects of humanity from an early age, benefitted greatly from his discipline...even if it was a discipline which fostered considerable personal power.
Anyhow, before I muck up any more threads with distracted thoughts...off to tend to my hungry boys.
Take care, all, and thank you for the great food for thought!