* The term “IQ” developed from the work of German psychologist William Stern
* The US army assessed the aptitude of 1.75 million men by giving them intelligence tests in the First World War. The resulting data indicated that the “average” adult had a mental age of 13
* Mensa, the club founded in 1946 for people “whose IQ is in the top 2 per cent of the population”, has 28,000 members in the UK
* The idea of many - or “multiple” - intelligences has been around since 1920. But it became popular in the early 1980s when Harvard-based educational psychologist Howard Gardner published Frames of Mind