Studies suggest that smiling makes people appear more attractive, kinder and, by some accounts, easier to remember.
All smiles share something in common: an emotional foundation. Depending upon what the emotion is, the brain sends different instructions to the face. The areas in instigating a polite, or voluntary, smile (the kind exchanged with a bank teller, for example) are not the same ones involved in a more emotional smile (such as the kind that emerges on seeing a loved one or hearing a funny joke).
However, regardless of what prompts a smile, the results are the same. Both you and the recipient are prompted to have good feelings.
Dr. Dale Anderson, M.D. prescribes smiling and even laughing a few minute each day to improve your psychological and emotional state. He will have you prove to yourself that changing your outside features changes your inside features as well.
Here is a simple test. Think of something sad. Now, with that sad thought in mind look up to the ceiling. Smile, and experience how quickly that sad thought disappears. You immediately feel better, and you become more attractive.