Comment by dns_snek

> Of course, everybody is on the autism spectrum, even people who show no symptoms (they are on the left hand side).

No, that's not at all how any of this works. People who don't have ASD aren't on the autism spectrum because the spectrum isn't an intensity meter where one end is neurotypical and the other end is non-verbally autistic with 24/7 support requirements.

It's called a spectrum disorder because every autistic person experiences different divergences/impairments to varying degrees of severity. Some people can have intense sensory issues but socially pass as neurotypical, others can have minimal sensory issues but really severe social issues.

The DSM used to exclude people who were clearly autistic but didn't align with any of the rigid definitions that were captured in the DSM as distinct diagnosis, that's why it was eventually recognized as a spectrum disorder.