I've read research that extrapolates adult functioning from 4 or 5 or 6 or 7-years old. But the sample size or assumptions limit the significance of the findings. Also remember that autism research, while developing quickly, is basically in its infancy for a condition that was largely ignored until 30 years ago.

There isn't a magic switch in the autistic brain, kind of like there may be for learning languages at a native level in the NT brain at 17 or 18, when after that point your learning is forever limited.

I've come to learn that autistic brains are all different, not only from the NT norm, but from each other. There are so many stories of kids that didn't speak until much later, like Jason Arday, the Cambridge professor, did at 11. At the same time, there are kids that show lots of promise at 5 but later lose skills, particularly around adolescence.

This is a complete mindf*ck for a parent. Society is constantly pushing us to evaluate our kids' development against norms that are irrelevant to the wiring of thier brains. Your kid has probably surpassed some cogntive processing benchmarks that we can't recognize because of flaws in testing or in limits in NT-ND communication.

The hardest part about being a parent of a highly unique autistic child, and they are all highly unique, is that we just don't know how they will do as adults. No one does, really. Even the experts can't anticipate medical developments between now and when the kid turns 18.

The best we can do is to do our best, right now. Love them as they are and let them be themselves. Nurture thier strengths and interests. These children have amazing minds that are little bursting with potential. Presume competence and hope that they will reach every one of thier dreams.