This question is an exact duplicate of:
I am working on a story. I just want to know, will it be good for humans and for the development of human society to hide their facial emotional expressions from others especially strangers?
If that's good, please provide the points on how far a human should avoid show their emotions? I mean should that boundary of expressing has to be just with their family?
And if that's bad then please provide why it's bad?
Well I feel that a person could also be judged as whether he is weak or strong on seeing his facial expressions. So I feel its better to hide their expression based on the above point.
Let's just consider that the background of my story has fantasy characters living along with humans. And while answering please also add points not just about facial expressions but also on expressing a persons emotions.