I also find the spread of autism terrifying. My wife works at a kindergarten and she has had to deal with children that have problems from the autistic spectrum, healthy enough to be allowed to integrate in a normal collectivity, problematic enough that adjustment is very hard - they simply stand out from everybody else. And she noticed an interesting pattern, those children usually come from families of engineers, mathematicians or software developers.
And maybe the sample is not representative of the general population, but it scares the bejesus out of me, especially since we have a son that is happy, loving, socially apt, smart and healthy, but that was a late talker and at 4 years old he still does mispronunciation for many words - this is another recent trend.
I have read a book at some point, can't remember the title, but especially in boys you have brain parts specialized for certain tasks and this happens when you've got certain parts of the brain underdeveloped, with maybe other parts overdeveloped. It usually goes away, once the child grows. Maybe this is just an evolutionary step, or maybe we are broken, I don't know.