In Laughter, philosopher Henri Bergson tells the story of a man who witnesses a sermon so moving that it brings the entire congregation to tears — except him. When asked why, he replies that he’s not from the parish. Does one have to “belong to the parish” to laugh, as one does to cry? 
Is humour universal? Why do people everywhere tell the same jokes, merely changing the nationality of the characters? Or are there cultural humours — identity-based humours? Perhaps in every tea, only one kind of fly falls.