If you consider the “true ability” to be the exponential of the subtest scores, then the extent to which the problem I mention applies depends on the base of the exponential. In the limiting case where the base goes to infinity, only the highest ability matter, whereas in the limiting case where the base goes to 1, you end up with something basically linear.
As for whether it’s a crux, approximately nobody has thought about this deeply enough that they would recognize it, but I think it’s pretty foundational for a lot of disagreements about IQ.
If you consider the “true ability” to be the exponential of the subtest scores, then the extent to which the problem I mention applies depends on the base of the exponential. In the limiting case where the base goes to infinity, only the highest ability matter, whereas in the limiting case where the base goes to 1, you end up with something basically linear.
As for whether it’s a crux, approximately nobody has thought about this deeply enough that they would recognize it, but I think it’s pretty foundational for a lot of disagreements about IQ.