70-year-old Linda LeVier credits laughter yoga with her survival: three years ago, on April Fool's Day, she had a heart transplant. LeVier believes laughter, especially the deep kind that starts in the belly, helped her recover with no complications and no signs of organ rejection.
The difference between fun and laughter? You can have fun without laughing. Some people, sadly, can even laugh without having fun. To my knowledge, there are vast collections of studies about the healing powers of laughter and humor. But I still haven't found anyone researching the physiological, psychological or sociological benefits of fun.