"to restrict or narrow conditions under which interfering behaviors occur (eg, modifying the learning environment); and
to reduce interfering behaviors (eg, self injury or stereotypy). "

I get why self injury is bad, of course. But why would the stereotypy be negative, if the kids were taught to ignore it? Don't give me the muck about schools enforcing conformity; I already know of it and hate it.

Stereotypy, I would like to hypothesize, is a form of nonverbal communication that non-autistics use so rarely, that to see it used so often, with the infamous Autistic attention to detail, creates a language barrier.

Normal people who feel like that expression implies do so much more rarely, so it must mean something different, or nothing at all.

Yeah right. And they say WE have bad theory of mind.