Of course, certain kinds of Americans, especially members of the left-leaning intelligentsia, can be every bit as ignorant of America and just as prejudiced or deluded about it as the silliest British newspaper pundits. I've heard plenty of American foreign correspondents and even State Department diplomats tell me that they could never live in America again, the implication being that they are now simply too cultured and sophisticated to live among their provincial, hamburger-eating fellow countrymen. And even within the US there are many upper-middle-class New Yorkers, Bostonians and Los Angelenos who like to characterise "flyover country" as a terrifying haven for inbred bigots and ignoramuses. These people tend to have little first-hand knowledge of Middle America. They know rural America from Deliverance, Blue Velvet and Easy Rider. They know how hellish suburbia can be from Desperate Housewives and the even more ridiculous American Beauty. Indeed, I've often been struck by the way British students on their gap year visit more American states than supposedly well-travelled Manhattan sophisticates do in their whole lives. If they had, they might be struck by the friendliness, decency and humility of Middle Americans. If some New Yorkers and Los Angelenos believe that everyone in the hinterland dons sheets and burns crosses of a Saturday night, it is because much of what they know about such Americans comes from television programmes made by people with the same prejudices. The idea that the heartland is both bland and dark, or dull and terrifying, makes a certain kind of East Coast urbanite feel immensely superior. These people have arguably been proved wrong by the election of Obama, and it may be you will hear less jokey talk about why New York should form a new, separate country.

I'm not sure if anti-American Americans are more common than anti-British Britons, but they are probably more dominant in academia and the media. Certainly they are very powerful in Hollywood. It's telling that the latest Bond film, Quantum of Solace, which runs counter to the traditions of the previous Bond films and books by putting the CIA on the side of the bad guys, along with multinational corporations, etc, and implicitly supporting the likes of Hugo Chávez, was largely written by the left-wing American (albeit Canadian-born) screenwriter Paul Haggis.

Stereotypes can persist long after the inspiration for them has disappeared. In Britain you still hear talk about fat American tourists even though obesity has become a problem here too. In America people still expect British visitors to be well-mannered and cultured, despite the arrival of the loutish British equivalent to the ugly American. In general, both Britons and Americans expect the other to be more like them. This can deepen the shock when they encounter some cultural differences they might not even be aware of if they were visiting a European country whose language they didn't speak fluently. This doesn't in any way diminish all the many profound things our two nations have in common. It's like the differences people encounter within their own family. On the other hand nobody appreciates America like a Briton who loves it, and no one loves Britain more than Anglophile Americans. Thank goodness, there are plenty of both.