In the 1980s the psychologist and philosopher James Flynn noticed one of the most striking trends of the 20th Century: that IQ scores have increased by about three points per decade, across the globe, for as long as we’ve had recorded tests.
In his latest book, “What is Intelligence?” Flynn continues to refine reasons for the increase – and in doing so debunks the idea that IQ measures a genetically controlled quality and that any racial differences are deterministic.
Flynn notes that the very fact that there are significant generational gains in IQ means that the scores cannot be ruled by genetics.
Flynn found that the highest gains are not on subtests that measure vocab and arithmetic, but rather on culturally-loaded subtests with questions like “How are dogs and rabbits similar?” that can illicit different answers depending on one’s everyday life experience.
Flynn says our modern lives are more cognitively demanding and so we’ve acquired something he calls, “scientific spectacles.” Today, we are more likely to answer using abstract categories, like, dogs and rabbits are mammals, rather than the more concrete, like, dogs and rabbits are pets.
(The former by the way is considered the “correct” answer.)