A quick digression on expectations (we’ll return – almost as a recurring theme — to the importance of teaching and teachers later). In 1968 Robert Rosenthal conducted an experiment in America where teachers were told that randomly selected pupils had actually performed in the top 20 per cent of a test that identified ‘potential’. This was, of course, untrue. But here’s the thing: when those pupils’ IQs were tested at the end of the year, they had increased relative to everybody else. Expectations improved performance.