There are many reasons why you should make "smiling your favorite". A sad face or a smile can produce the feelings that the expressions represents. So choose to smile. Do you truly understand the affect smiling has on others and on your well-being? When someone smiles at you, the bigger your smile becomes. It is contagious.
People who smile often have a more positive effect on their surroundings, and are received better by others. They are generally more optimistic. The research is clear, studies show that there is a definite link between optimistic attitudes and good health. An optimistic outlook can strengthen your immune system thereby increasing the body's ability to fight off infection and disease.
Smiling also helps to reduce symptoms of stress and anxiety. Happiness can be infectious. You can spread or receive it by surrounding yourself with positive happy people. People are typically as happy as the five people they spend the most time with.
Smile more often and start the out-pouring of smiles around you. You will not only help yourself, you just might help someone else.
One Class can change your life to stay healthy, "way2wellness"

Smiling is fine and good for health wise as you pointed out, but do you think is ethical to fake smile? just for health sake.