Dean Burnett

Louis Leon Thurstone in 1938, who proposed that human intelligence was made up of seven Primary Mental Abilities:

If you get really good at something then your brain becomes so efficient at it, it essentially stops realising it’s happening. And if it doesn’t know it’s happening, it won’t adapt or respond to it, so you get a self-limiting effect.

Genetics, parenting styles, quality of education, cultural norms, stereotyping, general health, personal interests, disorders; all of these and more can lead to the brain being more or less able or likely to perform intelligent actions. You can no more separate human intelligence from human culture than you could separate a fish’s development from the water it lives in. Even if you were to separate a fish from the water, its development would only ever be ‘brief’.