Outgrowing autism?

This discussion got me wondering...

How common is it for people to "outgrow" autism?

What counts as "outgrowing?"

How many people who "outgrow" it "grow back into it?"

What is it in the multi-faceted nature of autism that would allow some cases to be magically "outgrown" and others not?

If it means simply not fitting the diagnostic criteria for an ASD anymore, then it's likely that my boyfriend has "outgrown" his Asperger's for the intents and purposes of documenting recoveries or remissions. But he still has some quirks that I don't think can simply be written off as results of a strict upbringing. His sister grew up in the same household and seems to have the same functional attitudes toward social and interpersonal stuff as just about any neurotypical - for instance, the attitudes of moral flexibility and non-excessive fear of angering one or two friends that are mysteriously absent in my boyfriend. Also, she can presumably handle indirect communication from others and not dominate a conversation involving more than 2 people. (At least from my perspective, my bf doesn't seem bad at letting me talk in one-on-one conversations, although he may not let things stay quiet for long, unless I fall asleep in the car or something.)

But do any of these people truly become NT, rather than subclinical neurologically quirky folks or autistics who can pass for NT? If so, then their "autism" may have been a different beast from the kinds that people don't outgrow.

I've sometimes wondered if my bf's childhood sensory integration issues were related somehow to the epilepsy he had in adolsecence, such that he outgrew both once he outgrew the epilepsy. And, no longer having the sensory integration issues, he'd only be autistic by memory. But his attachment to his memories of his autistic younger days might be a lingering sign of autistic cognition, i.e. imprinting on his early impressions of what slimy foods and hot shower water on his head felt like and so feeling he must still avoid these things...or just the kind of thing you can expect from anyone who had a difficult time of anything in their youth, being afraid to revisit whatever it was.

People's brains rewire all the time. It's often called "learning," or in some cases involving young people, "growing up." Maybe some brains just "learn" how to integrate their senses after getting off to a slow start. I think I once read NT tots tend to go through an autistic-like phase of being stuck on detailed rituals and favorite objects. Here is a page on NT toddlers at 18 months...about the time autistic toddlers tend to stop talking and start playing with tiny parts of objects. Apparently, NT babies at this age are highly fond of stimming that would be unacceptable in older children and favorite objects. And 17 month old NTs tend to be finicky eaters kind of like many older Aspies. Hmm. So, at least in a certain age range for most people, the brain rewiring in ways that promote fewer autistic-like behaviors is something that happens naturally.

So maybe there's a kind of developmental course, probably a rare one, that allows for a kid to be diagnosably autistic at one age and then just grow out of it and leave few signs of having ever been autistic...fewer than my boyfriend, who was at the very least on the spectrum (or an "autistic cousin" with strong symptoms) until puberty.

It's all speculation at this point. Even studies can be tricky when it comes to such soft, interdependent variables as one might expect in a range of conditions with somewhat similar outward symptoms that are all lumped together under a social construct.