Neurotypical (non-autistic) people are fond of functioning labels – high/low, etc. But autistic people themselves do not like to use functioning labels because they are inaccurate. Functionality is not a constant with autism – it is fluid, situational, often inaccurate. Is someone “high” functioning because they can talk? A yes to this answer discounts the intelligence of someone like Stephen Hawking (who has ALS) – if you take away the machine that talks for him, is he suddenly “low” functioning? His body, yes – but his mind? Autistic blogger Carly Fleishman is another example of the inaccuracy of functioning labels.
If you know one person with autism, you know ONE person with autism. To advocate for others, we need to resist the “appeal” of using functioning labels, expand our perceptions and perspectives, try to understand the challenges people on the spectrum face daily, and work with them to maximize potential/minimize discomfort.