From the first line of the Wiki article: "The g factor (also known as general intelligence,...)" I was referring to g, not to the concept of general intelligen

From the first line of the Wiki article: "The g factor (also known as general intelligence,...)" I was referring to g, not to the concept of general intelligence, which very obviously has pretty much always existed. Apologies for the ambiguity. In any case, I don't think it really matters how precisely or reliably we can actually measure g directly, which is really what your sticking point is. Every important decision we need to make around the idea of general intelligence has to do with 1) whether it exists, 2) how well it correlates to positive outcomes in life under specific social and economic regimes, and 3) how heritable it is. All of these seem pretty darn obvious from various experiments not relying on measuring g directly. Why do you think it matters whether we can measure g? What decisions are there to be made with that information?