I used to be very sarcastic. But I have found that it is a caustic type of humor used to belittle people.
The belittling is the trait I find in line with the other habits of Britishness, it is to keep people within their social class. I know the class system isn't as obvious anymore, but I think it remains prevalent - people might want success for you, but only within a very tight band of acceptability, and if you threaten the status quo by attempting to move up the ladder you are belittled. Furthermore when you fail, you are mocked (using sarcasm) rather than applauded for trying.
America on the other hand, is the land of opportunity, high fives and freedom. To the Brit this seems cheezy (IE it is mocked because actually being positive about success is uncomfortable).
EDIT - You might not notice it if you are immersed in it.
The belittling is the trait I find in line with the other habits of Britishness, it is to keep people within their social class. I know the class system isn't as obvious anymore, but I think it remains prevalent - people might want success for you, but only within a very tight band of acceptability, and if you threaten the status quo by attempting to move up the ladder you are belittled. Furthermore when you fail, you are mocked (using sarcasm) rather than applauded for trying.
America on the other hand, is the land of opportunity, high fives and freedom. To the Brit this seems cheezy (IE it is mocked because actually being positive about success is uncomfortable).
EDIT - You might not notice it if you are immersed in it.