As far as innate potential, I suppose I'm a bit more agnostic than some here. I don't think I believe in a fixed, immovable g set in stone at birth or age 3 or whatever. I think time and experience have a way of having their way with us, for good and ill. I think there is a range of capacity for each of us. It certainly is HARDER or EASIER for people to do or understand some things than others. But often I think we decide people are incapable of things when they've had bad teachers or have been unmotivated.
The point of this entire conversation is that there is a fixed, immovable *limit* on the *upper point* of that *range of capacity* for any particular person.
And one problem is that it's not a fixed limit as such.
Modern IQ tests are largely derived from the military's AFQT. The AFQT exists solely to predict success in a variety of training schools. The more challenging schools have higher AFQT requirements to attend, in order to avoid wasting resources on recruits who have little chance of succeeding.
Those students selected for advanced training, based on their higher AFQT scores, still fail at a significant rate. The US Navy's most challenging school, nuclear power school, has so many failed students every year that they've been given a colloquialism: "nuclear waste."
The Navy's data tells them that this is to be expected, because they've been doing this long enough to see that an AFQT of X will yield Y% of successful graduates, as X goes down, so does Y, and it's not so much a hard limit as it is a continuum (although obviously their data set doesn't follow the numbers all the way down to Y=0).
Caution: Made up numbers below for illustration only.
So, if 40% if recruits with an AFQT of 85 can successfully graduate nuclear power school (or conversely, that 8% of recruits with a 99 AFQT fail), that says:
1) AFQT is telling you
something.
2) There are other factors involved for the 40% of students who succeed/8% who fail, with ability being equal.
Whenever we talk about success and failure among individuals with equal levels of ability, we inevitably start talking about personality traits relating to increased effort: perseverance, grit, motivation, work ethic, etc. Those are traits that a growth mindset seeks to promote.
