why people laughs??

Good day,
I had just read an article about laughter. Have you all wonder why people laughs?? Here is some of the information that i received.

Laughter is an audible expression, or appearance of merriment or happiness, or an inward feeling of joy and pleasure (laughing on the inside). It may ensue (as a physiological reaction) from jokes, tickling, and other stimuli. Inhaling nitrous oxide can also induce laughter; other drugs, such as cannabis, can also induce episodes of strong laughter. Strong laughter can sometimes bring an onset of tears or even moderate muscular pain.

Laughter is a part of human behavior regulated by the brain. It helps humans clarify their intentions in social interaction and provides an emotional context to conversations. Laughter is used as a signal for being part of a group — it signals acceptance and positive interactions with others. Laughter is sometimes seemingly contagious, and the laughter of one person can itself provoke laughter from others as a positive feedback. This may account in part for the popularity of laugh tracks in situation comedy television shows.

People says that laughter is the best medicine. I do agree on that because when u laugh u can really cheer yourself up. All the worries will suddenly disappear. So, do not be shy to laugh. Just laugh out laud. (^_^)

Resource from:
http://findarticles.com/p/articles/mi_hb140/is_199802/ai_hibm1G120156486