Psychologists say:
When you see someone laughing a lot and sometimes something almost trivial you know he is sad.
If you see a person speak quickly, so know that he is innocent.
The person who smiles at people's faces is a person with a good heart.
My smile scares people... So this just isn't a fair judge of my heart. I guess I match the first two though, got the sad part right, not sure about innocent.