Intelligence turns out to be mostly one-dimensional -- in other words, most of the difference between people can be described by a single number. More complica

Intelligence turns out to be mostly one-dimensional -- in other words, most of the difference between people can be described by a single number. More complicated models with more numbers exist -- they do work slightly better but at the expense of being much more complicated. (This is literally textbook science and not something "all sorts of idiots are [...] delusional about".)