'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 don't think marrying a billionaire heiress is the best way to get into Google.

The limits of Friedman's understanding should come as a surprise to no man.

I dislike Friedman a fair bit, but I can't hold this one against him: restriction of range is a subtlety that pretty much no one understands in interpreting correlations, and I only know about it myself because I happened to read a paper torpedoing a previous famous paper as having fallen prey to restriction of range (and then did some more reading on range restriction).

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.

Easy. Think of Sheldon from Big Bang Theory. He may have a high IQ, but he lacks the ability to be able to connect different ideas and/or come up with solutions which require more than just processing mathematical computations.

I don't think its a good idea to let your world view be influenced by fictional T.V. characters.

What kind of fictional characters should I allow to influence my world view? Those from books written in the 20th century? Shakespeare? The Illiad? Any advice appreciated.

I'm not, he's just an example which I thought best sums up what I am trying to describe...

Can you give an example of someone in the real world who has "a high IQ, but lacks the ability to be able to connect different ideas and/or come up with solutions which require more than just processing mathematical computations"? IQ is not a measure of arithmetic processing capability.

Probably not one you know well...

Setting aside the psychometrics discussion, it's illegal in the US to hire based upon IQ tests.

Not exactly.

http://laws.findlaw.com/us/401/424.html

Not to mention http://abcnews.go.com/story?id=95836

P&G uses an iq-like test from what I've read. The NFL uses the Wonderlic iq test.

"Legally difficult" would have been more accurate.

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".