Asked by: Amber de Giorgio, by email
There seems to be no definitive answer.
The International Society for Humor Studies' website provides no information on the subject, while the list of jokes provided by the Association for Applied and Therapeutic Humor only made things worse. When I searched through categories of jokes on the internet, though, one thing stood out. Sadly, it was the ethnic joke, devoted to making the inhabitants of some other country appear inferior. Every country seems to have them, from English jokes about the Irish to French-speaking Canadians' jokes about people from Newfoundland.
A typical joke about (a particular country) concerns their scientists who were building a rocket to fly to the Sun. When asked how they were going to cope with the Sun's heat, they answered disdainfully, 'We're flying at night, of course'.