In Ancient Times the Greek philosopher Plato was the first one to give an answer to the question why do people laugh. He stated that you are laughing because you are feeling better the person in front of you. According to Plato laughing equals laughing someone out.

After Plato many other people have been thinking about laughter and humour.

You laugh because you want to create a bond with the other person, to let the other person know how great you like him or her. If a friend tells you a good joke, you probably will laugh very loudly. But will you also laugh when the joke is being told by your not so friendly neighbor ?

The Jefferson theory.

The theories discussed so far are all from the l point of philosophy/psychology. Every theory tries to give a convincing answer to the question what humour really is. The theory by Gail Jefferson (1979), is contrary to this, this is because it only occupies itself with the question of how laughter interacts with conversations and what functions it might have.
According to Jefferson, laughing is an activity whereby one participant invites the other participant(s) to laugh. This invitation can be accepted or declined by the other.

What do you think about this theory?