The public debate over academic selection at 11 has once again ignited. Professor Chris Husbands wonders why, when all the evidence argues against this approach to education.

UK Secretary of Education:

It is a persistent undercurrent in English educational debate, but it is peculiarly English: should academic selection at the age of 11 be restored?

Boris Johnson, perhaps in response to perceived UKIP pressure, has declared himself in favour of more grammar schools, and Teresa May, more cautiously, has welcomed plans for a satellite grammar school in her constituency of Maidenhead. In Kent, the Weald of Kent grammar school is preparing a new proposal to establish what is either (depending on your view) a new grammar school in Sevenoaks or a satellite site in Sevenoaks.

The arguments for restoring grammar schools are couched in terms of opportunity and social mobility: Boris Johnson called them mobilisers of opportunity. But the evidence to support this is almost non-existent.

There remain 164 grammar schools in England, and their socio-economic make up does not support the proposition that they turbo-charge social mobility: in all areas where there are grammar schools, the proportion of pupils on free school meals (FSM) is significantly lower in the grammar schools than in the area as a whole (1).

There’s little evidence to suggest that grammar schools work in the way their proponents suggest: research by Professor Ruth Lupton found that grammar schools work well for those who attend them, but few FSM pupils succeed in doing so. Moreover, the OECD international evidence (2) is clear that early selection is associated with lower performance, particularly from more deprived social groups.

More fundamentally, the argument for grammar school depends on four assumptions all being true. The first assumption is that a test for academic ability at age 11 can be reliable; that is, that a test at age 11 will reliably discriminate between those who are academically able and those who are not.

Related: small learning communities and English 10.