Ahh, but you're not being fair, comparing Jewish humour with British humour.I have to say, I will take Seinfeld humour over most British humour.
Besides, British humour is mostly self-insultive. True humour is like that - laugh at yourself, and the world will think you're pathetic. Or something like that.
British humour is about the use of understatements, word games, none-sense and stuff like that. It can be either very stupid and simple, or very sophisticated, yet the origins remain the same.