Nice, I didn't know other people's emotes could effect me, pretty cool.
That said, what I'm experiencing is definitely not that, it happens too frequently when I'm alone in story areas and one time while I was in the middle of the Dune Sea on the transport speeder, just stood up in my seat to clap then sat back down.
It's not always claps, sometimes it looks like I'm high on spice and trying to tell someone I love them with hand gestures, or sign language like I'm tying to tell Tuskans I'll trade them a pair of binocs to pass over their land.
It happens when I'm autorunning and using the mouse to turn myself alot if that helps the troubleshooting.