I was trying to find some stats on the distribution myself, but couldn't find anything. All the data that's easily searchable is about people who have ASD :/

> Is it just that autistic people get more tired from the standard social guessing game? If this is a spectrum, then where is the cut-off? Is it all self-diagnosis then?

I guess so, I'm no expert on this myself, just know that I'm relatively high on the spectrum, but below this "magical" threshold you mention. From personal experience most social interactions for me are very tiring, especially around non close friends/family. However I can't comment on whether this is normal for most people since I've always been this way. I self-diagnosed myself through literature and a few online tests, but it's obviously not as accurate as a real diagnosis done by a professional. You can try to self-diagnose, but you obviously have to take the results with a bucket of salt.

>Also, what is stimming?

Short for stimulating. Basically engaging your senses to make yourself feel calmer/more comfortable. This explains it in more detail: https://en.wikipedia.org/wiki/Stimming