But this attempt to stop the British people understanding the class differences underpinning the election campaign is part of a wider effort to stop us understanding how our society still works. Cameron keeps saying class doesn't matter any more, and "it's not where you're from that matters, it's where you're going." But today, a child born into a poor family has to be 20 IQ points smarter than a child born into a rich family to have the same income when he is an adult. To a kid born in east London, the glistening towers of the City – just a 10-minute walk away – may as well be on a different planet.