Of course I also stim for the typical reasons, but I feel like I’ll sometimes sort of “play up” certain autism-associated traits as a form of body language… I’ve also experienced people not understanding what stims are and misinterpreting mine, so maybe it’s a bit naïve of me to do this.
I feel confident that my leg bouncing thing is associated with stress and/or nervous energy. I have another finger-waggling (often while looking up) thing that I do when problem-solving. I find it weird looking at myself in the third person and noticing the weird things I do… frequently apologising for it.
Of course, I’ve tried to control it in the past. It always starts subconsciously, and even when aware of it it’s difficult to stop. I don’t think I’ve ever done it intentionally.