Continuum said:
British humour has intelligence. I can't say too much for the latter.
I would disagree with you there (this coming from an English person). I would say that the one of the main differences is that American humor is more obvious, while British Humour tends to be more sarcastic and, apparently for Americans, harder to see.
British humour is often about how unsatisfactory life is, followed by how amusing this is when looked at in an abstract way. In my experience (I do not claim to be an expert, I'm just loquacious), Americans don't see this as humor, they seem to see it as complaining and just stating events and occurrences.
I often find myself not laughing at American humor because I find it too obvious. I would explain this by saying that American humor drawn too much attention to itself for my taste. British humour I have always found is more subtle. This is not a matter of intelligence, but of taste. (btw i used humor to refur to American stuff and humour to talk about British stuff, just to be clear)