But even those who do not see themselves as members of a particular grouping would recognise that social class still matters. Britain at the end of this century is nothing like as class-ridden as it was at the beginning, but it is still excessively class-conscious.
In a sense, this is a good thing. At least we have none of the hypocrisy of the United States, a nation built on the myth of social mobility - a promise which is, for most Americans, as illusory as that of the lottery. There is much truth in the old cartoon: Person A: "I'm reading a book about how the American class system operates." Person B: "I didn't know there was a class system in America." Person A: "That's how it operates."
No one has any doubt about how the British system operates: private education and inheritance are the system's two transmission mechanisms, the unspoken closed shops of various of the highest-paid occupations its defences. But the system has always been fluid enough to avoid the build- up of real class hostility, and the finer gradations of class distinction in Britain are breaking down.
Perhaps the most disappointing of ICM's findings is that only 1 per cent of people think of themselves as upper class. This is the group whose foibles and eccentricities provide most entertainment for the rest of us, and their shortage forces mass-market newspapers to fall back on reporting the antics of low-rent celebs.
It is interesting that, when Gallup first introduced opinion polling into this country just before the Second World War, questions about class invited people to allocate themselves to a multi-layered hierarchy, including the "aristocracy", a middle class divided into upper, middle and lower and an intermediate category called "upper working class".
Those kinds of caste differences have been abolished by changes, and a greater rate of turnover, in the labour market and by the great post- war backlash against snobbery. The most significant victim of this backlash has been the upper middle class, with its great "public" schools and extreme RP accent. Even in the BBC, once its liberal annexe, the full RP accent has become unacceptable - although only for men: Anna Ford and Sue MacGregor are still allowed to talk posh.
The upper middle class may still have most of the money, but its members do not command the deference they once did. In this respect, British society does increasingly resemble that of the US, with the vast majority of the population effectively middle class, with partitioned minorities at the top and bottom. The state of British politics, always class-based, is a telling indicator of this. The word "class" occurred only three times in Labour's manifesto last year (except as in "sizes"). The first time was in Tony Blair's introduction, in which he dismissed "middle class versus working class" as one of the "bitter political struggles" that "we aim to put behind us". The other two were in relation to preventing the growth of an "underclass" in Britain, "a permanent have-not class, unemployed and disaffected from society".
And that is probably how most people see class in this country today: a large majority of haves, with minorities of have-nots and have-lots on either side. Mr Blair's attention to the causes of social exclusion is admirable, but it might be balanced by a little more attention to the breaking down of the real, but increasingly obscured, class barriers at the top end of the scale.
We are still some way in this country from judging people not by their name, school, accent or colour but by the content of their character. That would be a modern definition of class.