My understanding is that it is a large collection of traits and that a person might have no traits or possibly even 1 or 2 that are very minor and NOT be on the spectrum. Someone else might have 1 severe trait and be on the spectrum and someone else might need 5 traits to be diagnosed as on the spectrum. Don’t think of it as a continuous spectrum but more of a collection of traits that are of little or no severity to high severity where as was mentioned before, the person has little or no quality of life.