you need to make a quick assessment of an English shopper’s social class, don’t ask about her family background, income, occupation or the value of her house (all of which would in any case be rude): ask her what she does and does not buy at Marks & Spencer. I say ‘she’ because this test only works reliably on women: men are often blissfully unaware of the yawning social gulf between M&S knickers and an M&S patterned dress.
