Maybe this has been covered, but I just saw a post by X-rayed about this topic as it applies to astrology. I have used this skill to help me identify children on the spectrum, like my son, so I can approach them in a way that works for them. I'm curious if anyone else uses this skill in anyway or has information to share on this topic.
Sorry I forgot to add that the shape of their hands, especially the fingers, helps me spot them.
This has nothing to do with the spectrum and may be remote from what you're after, but the first thing that came to mind is back in the old says, short men were said to have Napoleon complex. This was only sometimes true!
Also, welcome!
I bought a book on this topic many years ago. From memory, it just focused on facial features and traits. It was fun to read, and I do remember in some cases it appeared to be accurate.