I find your post interesting. I've recently come across the Autism Spectrum Quotient - see

http://en.wikipedia.org/wiki/Autism_Spectrum_Quotient

and

http://aq.server8.org/

I am not autistic - but my score is much higher than average (~28 +-2). Maybe a high score predisposes people to shy bowel.

I'd be interested to hear how other members of the group score.