That reflects the rising temperature of the political atmosphere in the US, where right-wing opposition to health-care reform has fuelled raucous townhall meetings across the country where anyone daring to contemplate the possibility of a government-run health system is shouted down by dozens of screaming opponents.

Experts point to a variety of reasons for the apparent fall in civil standards, which prompted CBS News to come up with a report on 'America The Rude-iful'.

The recession has placed many under heavy stress, while the rise of the internet has fostered confrontational and provocative communications in which people get used to saying things they may never once have dared to utter face-to-face, says Jerry Bowles, founder of the website socialmediatoday.com.

'The web seems to turn most people into adversaries,' he says. 'This is particularly true for politics on the web, where the comments tend to run to the extremes. I find it scary.'

Chiming in on the falling standards is P.M. Forni, an academic who studies civility at the Johns Hopkins University in Baltimore, Maryland.

'American society is among the most informal in the world, and often that informality crosses over into incivility,' he says. 'Now, you add the informality of the internet to this culture, and all bets are off. It's an age of total disclosure and total expression, with very little concern for the feelings of others.'

Lizzie Post, whose family is well known in the US as the country's foremost arbiters of etiquette, does not see the sky falling.

'These three events were bad, but the reactions to them were significant in that people were not impressed,' Post said in USA Today.

She pointed to the actions of Beyonce, who later called Swift back on stage to complete her acceptance speech, as an example that common decency is still alive and well.

'Kanye stole Taylor's moment, but Beyonce stole it right back,' Post said. 'That's an inspiration for anyone who would let all this bad behaviour get them down.'