High Functioning vs. Low Functioning

My son was first classified as low-functioning at 16 months. He didn't learn to speak and didn't speak until he was 4. He banged his head on the wall and bars of his crib. He would scream if anyone would touch him, and he would not let anyone hold him, even as a newborn. It was heartbreaking. After he started talking, a lot of the self-destructive/self-injurious behaviors subsided (note that I said subsided, not ended). We had moved and his new doctor diagnosed him as just having autism, not low-functioning but not high-functioning either. The main differences were his frustration levels were lower and he was having an easier time learning. When he was re-tested at 15 years old, we were given the diagnosis of high-functioning. Now, we aware that the APA says children cannot move along the spectrum, but a lot of autism specialists, including Dr. Tony Attwood disagree. Damien still has all of the same difficulties as he did at 16 months other than the speech problem. However, he can keep them in check and control MOST of the time. He is fully inclusive but still gets special education services. He has a job at the zoo and does really well at work. As long he has the supports - checklists, pictures, color coding, etc., then he is able to function on his own. I truly believe the higher the functioning, the more invisible it is to the outside world. There will always be social difficulties, fine motor difficulties, and sensitivity difficulties no matter the functioning. I suggest checking out Dr. Tony Atwood, Temple Grandin, and Stephen Shore for an idea of what high-functioning is. Both Grandin and Shore are individuals with high-functioning autism.