All About Laughter
Laughter just might be the most contagious of all emotional experiences. What's more, it is a full-on collaboration between mind and body. Although laughter is one of the distinguishing features of human beings, little is known about the mechanisms behind it.
Scientists do know that laughter is a highly sophisticated social signaling system, helping people bond and even negotiate. Interestingly, most social laughter does not result from any obvious joke. Laughter is not limited to communicating mirth. It can be triggered by embarrassment and other social discomforts.
Laughter may have evolved to facilitate bonding across large groups of people. In primates, the grooming process releases chemicals that help build social bonds; humans eventually came to live in groups that were larger than the grooming process allowed. Laughter, as well as. speech, enables us to bond quickly and easily with a large community.