Asked by: Anonymous
Laughing may even have evolved for this function. It is highly contagious (even more so than yawning) and can help bring people together. This social function is obviously important for a species like us, and so we enjoy laughing. The mechanisms for this enjoyment include effects on the immune system, improved functioning of the blood vessels and heart, increased levels of endorphins in the brain which eases pain, reductions in stress hormones, and wonderfully relaxing effects on the muscles.