system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why we cover our mouths with our hands when we're shocked.

I always thought the cover-mouth-with-hand thing was some fabricated reaction invented by Hollywood. But I saw a car accident today and, out of nowhere, I genuinely did this. Why the hell did I cover my mouth with my hand?
gpt
It's the same reason we cover our mouths when yawning and chew with our mouths closed. It's rude and gross to show the inside of your mouth. You will notice that kids naturally open their mouths when they are shocked. It is only once we learn manners that we start to cover it with our hands.