Spend any time on the bottom half of the internet and the same criticism of journalists, politicians and power brokers pops up again and again in the comment sections. "You live in a bubble." "You don't know how real people live." Words to look out for include metropolitan, Oxbridge, latte-drinking, public school. Or, as Richard Littlejohn described those in favour of AV in the Mail: "Guardianistas, quangocrats, television and radio producers, and the kind of people you see wearing Afghan hats and distributing agitprop leaflets outside Tesco Express on a Saturday morning when the rest of us have something better to do."

To anyone familiar with Fox News or the oratory of Sarah Palin, it might seem that the US thinks of itself the same way: 99 per cent God-fearin', Nascar-lovin', fried-things-on-a-stick-eatin' honest folk, and 1 per cent quinoa-munching, abortion-having dissolute elites.

But Coming Apart, a new book by Charles Murray, a libertarian political scientist, questions that consensus. Murray is already a controversial figure for his 1994 work, The Bell Curve, which suggested that innate intelligence is a better predictor of income and job success than the education level or economic status of an individual's parents.

Coming Apart is just as combative: Murray suggests that blue-collar America is far less socially conservative than it's painted, while the rich bicoastal "elites", having flirted with counter-culture in the 1960s, are now really rather straight-laced. As the Wall Street Journal's review put it, a "marriage divide" is opening up across the US. "Since the 1980s, divorce rates have risen, marital quality has fallen and nonmarital childbearing is skyrocketing among the white lower class," wrote W Bradford Wilcox. "Less than 5 per cent of white college-educated women have children outside of marriage, compared with approximately 40 per cent of white women with just a high-school diploma."

Uniform rating

Even Murray's critics - and there are plenty - think he's hit on something with Coming Apart. Writing in the liberal Huffington Post, Jared Bernstein of the Centre on Budget and Policy Priorities skewered the "limiting and confusing way he uses data" before concluding "Charles Murray is right". American society, he agreed, is fragmented into the elite and the rest, even if their respective beliefs and behaviours aren't what we might expect.

So how do Americans know whether they are part of the new elite? Murray has devised a handy quiz. "Have you ever walked on a factory floor?" "Have you ever held a job that caused something to hurt at the end of the day?" "Since leaving school, have you ever worn a uniform?"

What would a quiz look like for Britons in the same boat? A few suggestions: "Have you ever used chopsticks?" "Do you regularly use public transport?" "Do you watch any of The X Factor, Britain's Got Talent or The Voice?" "Could you pick Danny Alexander out of a line-up?"