Obvious troll is obvious.
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Dave Trouser ; the people's choice - 75% agree, Mon 12 Apr 2010, 18:51,
archived)
Illnesses are acquired.
That's not a very strict definition, but it's as good a rough guide as I can give you off the top of my head.
Autism and the like are the result of congenital differences in the physical structure of the brain, I believe.
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Moon Girl Technologies horrendous beanbag, Mon 12 Apr 2010, 18:57,
archived)