Humans laugh mostly during conversation, rather than physical contact. As you would expect, people are more likely to laugh in social contexts. Obviously, social situations increase laughter. But contrary to researchers' expectations, Provine observed that most laughter is in the context of conversation, not as a response to any structured attempt to provoke laughter. Laughter mostly follows such lame remarks.
Many researchers concentrate on the audiences.
Provine studied the speakers, too. He found that, counterintuitively, the speakers laugh more than the listeners do and females tend to laugh more often than males . In contrast, a typical male speaker will laugh slightly less often than his female audience will. The most striking differences between the genders were found in episodes that involved female speakers and male audiences. In such instances, female speakers laughed more than twice as often as their male audience did.