I have just returned from Botswana, where it is customary to ask of everyone and anyone the question “how are you?”, followed by a long interchange of pleasantaries. Do that in England, and they call out the police.

But do you know what many of us in the UK see as the USA’s only great contribution to the world? The habit of saying “have a nice day” at the end of even minor intreractions. So long as it’s not said by a sales person!