HOW DO IQ TESTS WORK?
FABIAN MCNEIL, VIA EMAIL
In 1904, English psychologist Charles Spearman discovered there was a strange link between certain mental skills, such as mathematics, verbal fluency, spatial visualisation and memory. He found that people who did well at one tended to do well at others, while those who did poorly at one would do poorly at others. And his finding has been shown to be true so many times that it has been called “arguably the most replicated result in all psychology”.