"Your theory would also need to explain correlations between scores on different IQ tests taken by the same test-taker." I think that one is easy: In fact, @w

"Your theory would also need to explain correlations between scores on different IQ tests taken by the same test-taker." I think that one is easy: In fact, @waps has a bag of M questions, where M > 1000. To compose a new WQ test, he draws 1000 questions, without replacement, from his bag. Then the series of tests has some similar or even same questions. In such a case the scores must be correlated. This is not too far off-base. Especially when you consider that many questions are superficially different, but really the same. E.g., those "name the next number in the series" questions.