[Graybeard58]

However, this article seems to say that autism of some kind affects 12% of kids? That does sound awfully high!

Yes, that would be high but it doesn't say "12%", it says:

An estimated one of every 88 children in the United States has an autism spectrum disorder

That's a little over 01%.

[GeronL]

And many of those are only slightly affected

As a matter of fact I know people who seem a bit “off” but are almost normal otherwise. I usually chalk it up to the culture, but some of them could be slightly autistic, it make sense.