- Give you a more fulfilling and longer lasting marriage.
- Give you a greater sense of well-being.
- Make you more inspiring to others.
- Make you live longer.
- Make other people smile too.
- Make you feel happier.
- Give you a bigger hit of endorphins and serotonin than chocolate or money or even sex.
- Reduce your blood pressure.
- Make you more likeable.
- Make you seem more courteous.
- Make you seem more competent.
Check out this TED talk for a bit more detail:
Some more smiling research stories: