When I was a kid, you could tell someone was what they called autistic just by looking at them, or sometimes observing them a bit. Even with today's broadened definitions, Musk and Thunberg definitely stand out in some way, in their outward expressions and mannerisms; not so with Aykroyd, as far as I've seen.

The behaviors range from the most severe forms of autism, in which individuals are nonverbal and intellectually/developmentally stunted, to the mildest forms in which individuals may actually be intellectually gifted but evince social deficits and also certain atypical behaviors such as perserverence and extraordinary focus, even obsessive/compulsive type tendencies.

I've often wondered whether the extreme forms exist because of a possible evolutionary benefit the milder forms might provide.