JJ
I'm honored to be an ilk of Hammegk's. 
Actually, the burden of proof is on anyone claiming intelligence is more than one thing.
Really?
I am quite seriously not aware that IQ or some one other measure has been shown to be all-inclusive. I know you argue for 'g', yes, I do recall this, (see? even the stupid, according to some IQ tests, can remember something, and according to some of the tests, I'm a drooling idiot, so pardon my lack of faith in any given test...) I am still,however, unaware that the proposition that intellegence is ONE thing has been proven.
Until then, the burden is not mine.
To my knowledge, no one has ever done a factor analysis on a battery of tests where the single factor, g, has NOT emerged and sucked up most of the variance in test scores.
Indeed. This is, however, inferring causation from correlation in a very real way.
Now, are there different paths to getting the same 'g'? I don't think you've shown otherwise.
Add to that the fact that if the "IQ" test doesn't measure g then its validity crashes-- the test no longer correlates with SES, education, job performance, etc.
Well, then, would you like to tell us what are good tests? I do agree that tests SHOULD predict, but my experience with many tests (and I've taken many, I was for whatever reason a favorite subject of some of the cognative people back at the Labs) suggests that their results don't always exactly correlate, no matter what they are measuring, and no, I wasn't deliberately confounding the data.
It's fine and dandy to claim there are 7, 10 or 12 types of intelligence, but no one's ever designed a test that taps a specific other type of intelligence, but that does not also measure g.
So, a skill in basic math is equal to a skill in, say, convincing rhetoric? Or are people good in one good at the other? That hasn't always been my experience, for sure.
I think you could categorize cognition into various branches (math, verbal, spatial, etc) but you always have g on the top explaining the biggest chunk of the variance in individual differences on these branches.