No Smile Limit
Many national and local governments place a much higher priority on preventing crime than on promoting friendliness and cooperation. But facilitating friendship is often easy, cheap, and has an obvious impact on people's happiness – and also on their willingness to help others.
https://prosyn.org/qq5aTO1
If you were to walk along the streets of your neighborhood with your face up and an open expression, how many of those who passed you would smile, or greet you in some way?