National Humour

It seems that everyone knows that humour differs around the world, but nothing I've found online so far (still looking) can map it out exactly by types, or say what contributes to the differences.
I posted this on my facebook as well, but I'm looking for input.

So, to anyone who reads this: What do you think is unique about humour in your country compared to the rest of the world...and, if possible (you might have no idea, which is a valid response), what do you think helped to develop that specific variety of humour? Do you think it is based on national history, or geographic location, or something else entirely? If you reply to this, state your general location as well please...

This is mostly aimed to people outside of the United States, but anyone within it is welcome to respond as well--either to say "when I visitied ____ I noticed _____ about their humour" or "hey in my part of the United States _(basic location)_ I believe we are unique in that ______"

Thanks everyone in advance for any contributions. :)   Oh, and if you know of any specific examples of what you're expressing, feel free to either link me in that direction or tell me the name of something to look up.