It’s often dangerous to generalize, but under threat, I would say that Americans are more “down the line.” They don’t hide their hopes and fears. They applaud ambition and openly reward success. Brits are more comfortable with life’s losers. We embrace the underdog until it’s no longer the underdog.We like to bring authority down a peg or two. Just for the hell of it. Americans say, “have a nice day” whether they mean it or not. Brits are terrified to say this. We tell ourselves it’s because we don’t want to sound insincere but I think it might be for the opposite reason. We don’t want to celebrate anything too soon. Failure and disappointment lurk around every corner. This is due to our upbringing. Americans are brought up to believe they can be the next president of the United States. Brits are told, “It won’t happen for you.”
There’s a received wisdom in the U.K. that Americans don’t get irony. This is of course not true. But what is true is that they don’t use it all the time. It shows up in the smarter comedies but Americans don’t use it as much socially as Brits. We use it as liberally as prepositions in every day speech. We tease our friends. We use sarcasm as a shield and a weapon. We avoid sincerity until it’s absolutely necessary. We mercilessly take the piss out of people we like or dislike basically. And ourselves. This is very important. Our brashness and swagger is laden with equal portions of self-deprecation. This is our license to hand it out.
This can sometimes be perceived as nasty if the recipients aren’t used to it. It isn’t. It’s play fighting. It’s almost a sign of affection if we like you, and ego bursting if we don’t. You just have to know which one it is.