It uses more muscles to smile than to scowl. Be Green, Don't waste energy !
Smiling whether sincere or not can ease melancholy. The muscles in the face press against nerves that send happy signals to the brain which responds with dopamine & endorphins which are the happy chemicals. I go to joke sites often to relieve a down mood because I am out of cannabis. So somebody send me some until I can get to Colorado. =0}
why not encourage folks to increase their face exercises?