Worse ideas have been had at 30,000ft. On a flight more than 30 years ago, an aspiring young author had a thought and wrote four words on the first piece of paper that came to hand: Gryffindor, Hufflepuff, Ravenclaw and Slytherin. J.K. Rowling had just drafted the house system for Hogwarts School of Witchcraft and Wizardry on an aeroplane sick bag.

Each house, named after the founders of the school, had its own character and the children would be placed there by the Sorting Hat in a millinery Myers-Briggs test. Gryffindors were brave, Hufflepuffs were loyal duffers, Ravenclaws were hard–working and clever, and Slytherins were devious snakes. Or, as the Hogwarts staff room may consider them: gods, plods, spods and sods.

Houses at real schools may similarly acquire their own nature, shaped by the teachers in charge and the dominant personalities of certain children. The actor and author Sir Stephen Fry wrote in his memoir, MoabIs My Washpot, that certain houses at Uppingham, which he attended in the 1970s, were known for being scholarly or sporty. ‘One house might have a reputation for being messy and ill-disciplined,’ he wrote. ‘Another for being a hotbed of queering and tarting.’ Not perhaps a line for the prospectus.