Laughing is good for your respiratory system. This happens because when you laugh you relax your muscles. At one time it was thought that endorphins were secreted during laughter. That may be true but it still has not been proven. All of the other benefits above.
Laughter is infectious.
Both are good for your health. The latest research on the benefits of humor and laughing is being done by a team of researchers at Loma Linda University in Southern California. Dr. Lee Berk heads the team. At the Schools of Medicine and Public Health, Dr. Berk is a professor, preventive care clinician medical research scientist, and psychoneuroimmunologist. The following is a summary of Dr. Berk's research.