单项选择题

Michelle Dockery, the actress who plays Lady Mary Crawley in Downton Abbey, says manners have disappeared in modern Britain.
"Those old manners," she says, "such as men standing when women arrive at the dinner table or opening doors for you—are lovely, and it’s lovely when you see a man doing that. But young men wouldn’t think about that for a second because it’s not the culture anymore."
She puts it down to the rise of sexual equality, which I suppose might play a small part in the collapse of manners. But the loss of noble qualities is a minor element in a much bigger story. Over the last 50 years, the British have changed from one of the politest nations to one of the rudest.
Luckily for us, the old-fashioned image persists abroad of us as a bowler-hat-wearing race, obsessed with tea and cricket. Those misconceptions are swiftly cured by a visit to one of the pedestrianised fighting areas in any provincial town centre on a Saturday evening at the closing time of a pub.
Of course, the image was always a slight myth. The British have always drunk heavily, and sworn even more. But they used to have a double persona—the heavy drinking, swearing one, which would be replaced by the polite persona immediately when good manners were required.
That idea of public shame has disappeared, and is now even condemned as pretentious. Self-righteousness has taken its place—it’s OK to play a DVD at top volume in a train carriage/wear a luminous green vest at a funeral, because the offender thinks it’s OK. The only driving factor in these decisions is desire for your own pleasure rather than the desire to minimize the pain of others.
This selfish behavior is much more natural than the selflessness implied in manners. If we were brought up in the wild, we’d all behave like this. Manners are taught. And that’s the big reason why they’ve collapsed over here—and—survived much better in other countries. They’re not taught much here anymore by parents, on television or by public figures.
In his latest book on litter, Theodore Dalrymple explains why the British litter these days—because they haven’t been socialized properly. Dr. Dalrymple and most of his generation—don’t litter, he writes, because their mothers told them not to. It’s the same with the modern collapse of manners. The central idea of this passage is that ______.