Autism

I'm going to try so that my general views are adequately expressed across the whole message. If it looks like I'm being vague at some point, I'll be likely expanding on that point later.

(...) Well, stimming is a thing, right? I’m not claiming stimming is universal for autism; but if it’s associated with autism, then that’s a pattern, right? Autism has more stimming than the neurotypical control group?

You're far more likely to find stimming in autistic people than in allistic people, but you may find autistic people whose natural impulse for stimming gets shut down (for various reasons, such as bullying, ABA or trauma), or allistic people who, under certain (usually exceptional) circumstances, stim (such as someone who is more nervous than usual and their feet begin fidgetting).

What are symptoms associated with autism? Are there any? (...)

There are plenty. I'm willing to accept the vast majority of those you'd find in most manuals, but only as conditional indicators, not as the essence of autism itself. I think the stimming example illustrates well why.

Is autism mental only, or is it neurological? If it has sensory symptoms (once again not necessarily universally, but as a pattern more than neurotypical/control), that’s neurological, right?

Everything mental has to be neurological, by definition, at least until we find of mental processes capable of taking place outside of the brain. Perhaps a better way to frame the question would be: is autism something inherent to how some people's brains work (and therefore strictly biological and genetic), or is it something acquired (and therefore learned, and potentially unlearned)? I think autism, as the diagnosis you'll find in manuals, is currently troublesome because it mixes a lot of elements that are inherent to the specific brain, and others that are the result of maladaptation. If you go 50 years back to the past, you'll find that health professionals would commonly see autism as a disease that has to be overcome, or even unlearned, while autistic people in self-advocacy groups today see autism as an inherent condition, with contemporary doctors somewhat leaning towards the latter position.

In my view, at the core of autism there's neurodivergency (this is, aspects of the brain that function differently), that are usually met with resistance, inadequate adaptations or abuse, which usually has traumatic results, and autism as a diagnosis mixes up all indications of whatever was always inherent to that person's brain and whatever disorders were inflicted upon them. Monotropism offers an explanation of autism that can be used to understand what is behind the whole spectrum, including both the stereotype of the asocial, isolated genius, the non-verbal, completely dependent kid, and the vast majority of autistic people who aren't in any of those extremes.

What does “autism is a spectrum” mean? Does it mean autism varies some, or does it mean it varies indefinitely? If it varies some, where does the grouping end? If autism varies indefinitely, why is human =/= autistic?

It means that autism is a multi-dimensional condition that you shouldn't expect to exist the same way in two random autistic persons. There isn't a binary or numerical indicator that tells you "this is autism", the same way you would say: "this person has XY chromosomes, and is therefore genetically male", or "this person is below the minimum healthy amount of iron in blood, and therefore has an iron deficiency". If you create an objective, numerical method to decide whether someone is autistic or not, the people who pass it are going to score differently in plenty of areas, so a multi-dimensional graph would express express the results far better than one single number. You will may find that one autistic person may see their results vary somewhat from one point of their life to another.

In the end, whether someone is autistic or not (as currently defined by autism as a diagnosis) is subject to an arbitrary line where the judge says "this is/isn't autistic enough". I would be far more comfortable with a non-psychological test that determined how the person's brain works in relation to that of the average person, but we aren't going to see that any time soon.

How do you define autism? What makes an autistic person different from non-autistic people?

Already answered, I think

If autism is just “having a special mind”, then what’s the difference between autism and other neurodivergencies and statistically-smaller psychologies? ADHD? Mathematical genius/brilliance? Bipolar? Severe intellectual disability?

As mentioned earlier, I think monotropism explains autism the best, and it defines it as distinct enough than any of those other categories.

Remaining sort of neutral with my opinions, I still state that autism must be by definition a mental and/or neurological phenomenon, and that means it has symptoms or criteria of some kind. And if autism doesn’t, then it would not be finite, and that would mean everyone is autistic, and therefore it would be a useless label and “autism” wouldn’t exist.

This makes sense to me.

If you believe that you are neurodivergent, but you don’t share a not-insignificant number of relevant traits with another neurodivergent person, then you wouldn’t share a label. It wouldn’t mean you’re not neurodivergent, it means you should find another label. And if you can’t find one that fits adequately, I encourage you to explore your own symptoms/criteria and create one.

If this was specifically directed at me, I hope you no longer think I'm a good target for that message lmao. I got an Asperger diagnosis in my teens.