> Doesn't this just mean that IQ Scores don't measure what they're supposed to? My understanding is that IQ scores measure how smart you COULD be, all things considered.
Actually there is no precice definition of intelligence outside IQ tests. My psychology professor had a nice saying: "Intelligence is what an IQ test measures".
IQ tests in general have very low prognostic reliability, e.g. they neither say how smart you could be (neglected children can easily rise more than 20 points after living a a few years with a nurturing foster family) nor how successful you'll be in your professional life (where motives and motivation play a more important role).