"Smile!"

The following is a public service announcement: 

There are those who have made it their life's work to approach random strangers, and instruct them to "smile." Though the public appreciates your interest in gaiety, we ask that you refrain the practice. A smile is like a gift, a reward. You cannot ask or demand it of another human. While we suspect you mean no harm, in essence you are asking strangers to alter their face to please you. It is an insult to the intelligence of the one to whom it is asked. Life has likely taught them when and when not to apply the appropriate facial expression. They have managed to accomplish this fete year after year without you there to instruct them. Consider that the person may not be smiling because they are competent enough the know when not to. Maybe they lost a loved one, have gastrointestinal issues. They could be experiencing a raging personal itch. Perhaps they simply don't want to, or maybe they don't like you. Research seems to suggest a strong correlation between laughter and smiles to like and dislike. Maybe the person is angry. As a general rule angry people frown upon smiling. Literally. It is therefore, not a good practice to ask an angry person to "smile." You risk potential damage to your own smile, and the loss of your very own teeth.  

It is also possible some of the unsmiling persons among us have naturally angry features. There are other terms for this. Do your research. The point is, quit asking them to customize their appearance to suit your preferred mood. These are people. They are not your minions. They owe you nothing. If you insist on this practice then please expect the "unsmiling" among us to start handing out one word instructions of their own. "Scowl. Bathe. Diet. Flee. Trip. Scratch. Undress. Die." It's only fair they should have a say too.  Stop, before commands replace greetings. 

This is also an ideal time to ask those of you, who feel the need to point out to darker black people, that they "look so much better when they smile," to stop. They have seen a mirror, and are fully aware of the contrast between their skin and their teeth. You'd  never say to a pale person, "you look so much better when you tan." The practice is then one-sided, and furiously unwelcomed.  

Just stop all smiling advice period. Let nature communicate this. It will be okay. Humanity can handle these things without input.  

Finally, out of goodwill and because your intent is likely kind, try the following solution: If you want to see joy, spread it yourself.  It's been proven quite contagious. Spread Joy. Don't demand it. You will  see more smiles if you greet others with one of your own.