I went to a grammar school. Had I not done so, I doubt I would have gone to Oxford; I'm not one of those arrogant twats who thinks he would have "succeeded" in any environment. You might imagine, therefore, that I'd support new grammar schools as a means of increasing social mobility.

You'd be wrong.

One big reason for this is that I was atypical in getting into a grammar from a poor background. Chris Cook points out that in Kent, where grammars still exist, poorer kids are far less likely to attend them than richer ones. This corroborates work by Adele Atkinson, Paul Gregg and Brendon McConnell who have found (pdf) "substantive under representation" of poor children in grammars - a finding consistent with international evidence which shows that selective education increases inequality of opportunity.

My experience fits this. My school was two bus rides from home in a richer part of Leicester, and it played rugby rather than football - two powerful ways of signalling that boys like me were not welcome. (There were also astonishingly few boys from ethnic minorities; my school was the whitest place in Leicester in the 70s outside of a National Front meeting.) It was only when I encountered a great teacher in the sixth form that I even began to feel as if I belonged. And he wasn't an Establishment man: think of Mr Hector without the sexual peccadilloes.

Of course, equality of opportunity isn't everything (or even anything!) But there's no evidence that grammar schools improve overall educational outcomes either. Chris and Atkinson and colleagues show that those who attend grammars do a little better than they otherwise would whilst those who don't do worse, leaving overall effects more or less unchanged. This too is consistent with the international evidence.

All this poses the question: given that there's no good evidence that grammar schools improve either social mobility or overall educational outcomes - facts recognized by intelligent Conservatives - why is there still support for them?

One reason, I suspect, lies in the fact that private schools are so damned expensive. Some parents want to bring back grammar schools as a cheap way of ensuring that Tarquin and Jocasta don't have to mingle with the riff-raff. There is, of course, an element of wishful thinking here: people over-estimate the abilities of their offspring and the chances they'll pass the 11+. There's also, as Angela Rayner says, an element of "harking back to a mythical 'golden age'".

This mix of ignorance, atavism and wishful thinking is very much the same sort of thing that lay behind support for Brexit.