Well, since I've seen folks without a diagnosis, who certainly appear to be "normal," f**k their kids up royally...
And I've seen disabled people who were called freaks by all and sundry do such a good job of raising their kids that said children beat all the odds laid out for them by genetics, demographics, and the circumstances of their birth...
Maybe there should be tests and licenses to procreate, I don't know. Maybe you should have to demonstrate to a board of sane, logical individuals that you've got the sense the Lord gave a light-blinded lizard. That you'll do things like feed them and brush their teeth and not prioritize heroin over food and clothing. That you can sacrifice for them without making them think that the world revolves around them, and refrain from abusing them without bringing them up with no discipline at all, and teach them morals without teaching them to be self-righteous moralists overflowing with certitude.
Then again, anyone who would want to sit on such a board would probably be a self-righteous moralist overflowing with certitude, so...
It might be cruel, but I think I'll let natural selection handle it. It has, so far, served us better than human efforts to take control.
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"Alas, our dried voices when we whisper together are quiet and meaningless, as wind in dry grass, or rats' feet over broken glass in our dry cellar." --TS Eliot, "The Hollow Men"