One of the biggest things in trans-Atlantic interactions is the level of maturity of the cultures that exist amongst North America and Europe.
In the past 100 years, almost every single European culture has been tested considerably. World War Two was the big one, in fact, and even the UK was under threat by the Battle of Britain and so on. We've had our empires, we've had our heydays, our sailing the seven seas, and so on. This is reflected by a culture amongst Europeans of taking the piss out of each other (it's not just a British thing). If you watch American media, you can spot how Europeans are portrayed as having a humour at the protagonist's expense (particularly in comedies).
Meanwhile, the modern United States has not seen any real threat to its integrity or existence, and the US is still doing the whole thing of trying to conquer the world, with us cynical Europeans going "yeah, been there, done that". Americans in general are thus not a matured culture, all very young, eager and enthusiastic (which is why we're fond of the people I imagine), and thus being taken the piss out of is not really something Yanks do.
It's like if you watch American comedy. It's very HAHAHAHA SO FUNNY slapstick that requires a laugh-track to tell you it's funny (just look at Will Ferrel). Compare that to subtle British humour. Most Americans just don't get sarcasm.
