Why is laughing in a public place considered deviant behavior in some cultures?

Laughing in public, depending on the context and culture, can be seen as someone going against a trend. If you're in a place or culture where silence is very valued, you might be considered as someone who is not complying with social rules or someone who is breaking a social norm. It will also depend on the place that you are and the situation that might cause this to be the case.

All of the above! Apex