Sat in a philosophy class today.

[Splorf22]

Originally Posted by Alawen [You must be logged in to view images. Log in or Register.]

He is operating under the assumption that IQ tests from different sources are designed to correlate. That assertion has no basis.

I actually rechecked and didn't see this. Anyway I'm not sure you understand his point, maybe because its mostly technical and I'm not sure I can summarize it easily. The key idea he is trying to get across is that G is based on a misuse of mathematics. Maybe one way to put it is the difference between correlation and causation: because various tests are correlated you can run a regression and it will automatically spit out G. But G is just a mathematical artifact that doesn't necessarily represent anything physical, and he shows this in two ways: the fact that G fails confirmatory factor analysis, and the fact that a different model can give the same conclusions. Which is why you probably find his conclusion so wishywashy, he's not actually disproving G, simply saying that its not necessary (what makes it unlikely is the kind of neuroscientific argument I have been making).

Originally Posted by Alawen

More importantly, the entire article is devoted to debunking Spearman's unitary g factor model. If you've been paying attention, you will note that I, following Cattell, never mentioned that earlier model, and that I discussed the two-factor model, Gf and Gc. The more recent study I linked today identifies three distinct factors.

Well he mainly focuses on G but he also talks about the five factor model. Really the mere fact that his alternate model works already casts serious doubts on any other one.

What really gets my nuts twisted, though, is that after spending almost two hours reading his horrible prose and looking up everything I wasn't positive that I understood, he writes off the whole exercise as too distracting from his real work to finish and delivers a weak conclusion: he doubts that there is a general factor of intelligence, but he's been wrong before. Along the way, he pretty much trashes all social science. I bet he's popular with other departments at CMU.

Personally I think this makes him fun to read, but maybe that's just me [You must be logged in to view images. Log in or Register.]