I do the “raptor hands” thing pretty often, but– I think— it’s an acquired habit? I do it when my hands are dirty, to remind myself not to touch things. I think I started doing it in chemistry labs while wearing gloves. I have a couple of other “I’m wearing gloves and my gloves are dirty”-specific poses, too. One of the professors I TA’d for used to joke about me standing at attention in the lab.
The weird things I do with my hands unconsciously are mostly more pressure-y, like clasping my hands tight, or crossing my arms, or pinching my fingers together.