system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do throw our hand over our mouth when we see or hear something surprising/shocking.

I just got some surprising news and immediately did this. Does anyone know why this seems to be an ingrained response?
gpt
It's to with the fact your jaw drops when you are shocked/surprised. And that fact it's rude (or at least, was rude) to have you mouth agape in public, it became a common and natural response to cover your mouth when surprised. It's a learned response because we've always seen others do it.