Yep, but I'm ADHD, perpetual motion is very much the norm for me.
Fingers are exceptionally enervated, which is probably the reason they're such a go-to for most people... As it's actually super common for people to need to "keep their hands busy".
From drumming fingers, to flipping quarters or silver dollars, to praying on rosary beads, to manicures, to chewing on fingernails, to spinning or rubbing wedding rings, to cracking knuckles, to wringing their hands, to twiddling their thumbs, to knitting, to piano fingering exercises, to rolling a straw or pencil or cigarette... Even neurotypical people muck about with their hands & fingers when nervous, anxious, or bored. It's a form of self soothing for most people. Typically, the "stronger" the pressure? The more soothing it is. To the point that people cut themselves on their fingernails they're clenching their fists so hard, and don't even notice. But whether it's tapping, or holding hands, or using a punching bag? The pressure usually feels good when we're upset.
((Other highly enervated areas have similar things... Pressing your lips together, biting your lip, tapping something against your lip, "chewing" on pens/ pencils/ hair/ shirt collars/, etc.))
ADHD trick... If people are getting irritated? Find a similar thing that scratches the itch / fills the need that is so explainable that people don't even notice. Their eyes don't even pause, because it's drop dead normal. It's either the "what are you doing?" Or the annoying noise factor that draws people attention towards what you're doing. For playing with my fingers? In Catholic countries, I tend to carry rosary beads. Around musicians, I'll do fingering exercises. Etc.
Why autism popped is probably because of the keywords you searched for. Like "lump" is connected to cancer with superglue in search engines... Even though it's a commonly used word in everyday life.
