'Restriction of range'. When you look at the general population, from janitor to tenured professor, one of the single best predictors of job performance is IQ; but when you look at, say, 'MIT physicist grad students', well, they're all very smart, so when you look at the minor differences in intelligence between them, the scores barely correlate with their future success even though no one becomes a MIT grad student in physics without being terrifyingly smart. Because they have been selected on that trait already. Hence the apparent paradox.

(No surprise Friedman doesn't understand this; the NYT article on the Google findings did not explain this.)

I was surprised by that, too. I work in a lab that studies intelligence, and IQ tests are generally designed to measure G (general cognitive ability). It's like saying, "we're interested in measuring height, and I'm not talking about inches".

I'd imagine he's saying that they want to assess general cognitive ability in ways traditional tests do not.

The first problem with IQ is that especially for high IQ persons, let's say 125+, it doesn't measure well what most people understand as general intelligence.

The second is that it reduces the information about one's intellect to one number. People have different strenghts in pattern recognition, high-level thinking, creativity, analytical thinking, speed etc.

BTW, my theory is that personality traits have significant influence on intelligence. For example:

1) how pleasurable is it to learn new things

2) how pleasurable is it to think about problems

3) perfectionsim

IQ is a dirty word now. But even apart from it's "racist" connotations, it is still bad PR to use that term. Compare "I got to where I am because I am really smart" with "I got to where I am because I was able to develop good learning skills".