Whether they're talking "privately" on cell phones or listening to a private thumpity-bump-bump through earphones connected to their iPods, they can't relate consciously to others around them. One teenager pinpointed a major problem for The New York Times: "The best way for parents to teach their children to be polite and respectful is not just discipline but also providing a good model and being respectful themselves  -- of other adults and, yes, even of youth." But modern families spend so little time together that it's difficult to be a model, good or ill.

 One teenage driver killed a bicyclist the other day in Colorado because he was text messaging on his cellular phone while driving when he should have been watching the road. This kind of horrible carelessness is likely to be repeated as technology triumphs over good sense. At my neighborhood pub, I frequently see couples who not only don't talk to each other, they don't talk to anyone else -- because they're both talking into their cell phones.

 The father of famously bad manners was the 18th century French writer Jean Jacques Rousseau, who in the name of spontaneity, identified social formalities as the supreme villain for imposing limits on the noble savage. In his view, the tyrants of society ruined children, inhibiting their natural instincts with rigid rules of behavior. Fast forward two centuries, and a popular television cartoon depicts the winner of a burping contest who is rewarded for high achievement, and moves on to a competition for passing gas.

 Good manners have never been enforceable, but were once accepted because they underpin notions of right and wrong. Lynne Truss, whose "Eats, Shoots, and Leaves," a best-selling book about grammar, of all things, has followed it with a best-seller, "Talk to the Hand," about rudeness.

 "Just as the loss of punctuation signaled the vast and under-acknowledged problem of illiteracy, so the collapse of manners stands for a vast and under-acknowledged problem of social immorality. Manners are based on an ideal of empathy, of imagining the impact of one's own actions on others."

 Rousseau only thought he knew about "uncouth, unpleasant and rude." Five minutes on any street today, and he would beg for mercy.