>>16773235
"Intelligence" is what you might call a folk term, like "love". It has no clearly defined scientific meaning. It has a lot of different meaning in common language. Fundamentally it's another taxonomy of behavior. "Intelligent" is showing the most prudent behavior for the situation or at least knowing what the prudent behavior is.
When intelligence testing got off the ground with Binet, back then they were testing all kinds of questions you might imagine as signs of intelligence.
But there was always a camp who believed that "intelligence" is innate, for various reasons. That camp were embarrassed by the fact that early intelligence test didnt show any sign of anything that could be passed off as innate ability. So they sifted through all the test questions and results in pursuit of questions where the results most lent themselves to a hereditary argument, using factor analysis.
What they found was timed ravens matrices. So they made up a term "fluid intelligence" and claimed ravens matrices measure that, and that it's expandable to problem solving and creativity in general.
All other measures of intelligence went out the window. So the IQ tests that exist today are basically the result of hereditarians cooking the books and designing tests that only or mostly (depending on the test) asks question that give them maximum support for arguing heritability.
A side effect is that "intelligence" now is defined to peak at around age 18, make of it what you will.
Even so, after all those efforts, redefining intelligence to only cover the area with most promise for inheritence, even the claim that Ravens Matrix ability and "fluid intelligence" are from genetics is on shaky ground, because the well known Flynn effect actually applies specifically to "fluid intelligence" testing.