laughter

Laughter is a physical reaction in humans and some other species of primate, consisting typically of rhythmical, often audible contractions of the diaphragm and other parts of the respiratory system. It is a response to certain external or internal stimuli. Laughter can arise from such activities as being tickled,^[1] or from humorous stories or thoughts.^[2] Most commonly, it is considered a visual expression of a number of positive emotional states, such as joy อ่านเพิ่มเติม