While browsing through the footnotes of Charles Murray's latest Commentary magazine essay on race and IQ differences I ran across an interesting bit of trivia on Charles Krauthammer: Murray mentions that one of the highest scores he's ever observed on the "backward digit span" component of the Weschler IQ test was 12 by Krauthammer (and under less than perfect conditions).

A quick search turned up this scoresheet and percentile distribution (PDF) for the digits-forward and backward tests, which involve reciting strings of random single-digit numbers back to the examiner. The scoring system requires adding forwards and backwards scores together, but helpfully notes that the average person can recite about two more digits forwards than backwards. To roughly extrapolate Krauthammer's full score we must multiply his digits-backwards score by two and add his estimated digits-fowards score times two (12 x 2 + 14 x 2), which equals 52.

Krauthammer's raw score equates to a standard score (one component of Weschler IQ) of....well the scale stops at 164 for a raw score of 36! The standard score increments a steady 3.5 points for every additional point of raw score so we can extrapolate a raw score of 52 to a Weschler deviation IQ of about 220! However, this would place Krauthammer at eight standard deviations above the mean (rarer than one in 100 billion), so I think we can safely conclude that A) Krauthammer is a very bright guy; and B) that either this test is not well-calibrated for extremes or that Krauthammer's every political opination is nothing less than a scurrilous defrauding of all mankind.

UPDATE: Oops! The scoring starts at two digits rather than one, so Krauthammer's extrapolated raw score would be 48 (11 x 2 + 13 x 2) and his standard score 206, which is "only" seven standard deviations above the mean.

## Tuesday, March 28, 2006

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## 2 comments:

For what it's worth, this is a memory test, not an intelligence test. There's a lot of controversy over what a fair intelligence test is, but among all of the reasonable candidates, the rule of thumb is that every such measure tends to correlate positively with just about every other measure, but not perfectly.

In principle, a person might have the best memory of anyone who ever lived, but average or even below average ability in doing things with all of that information. There's no reason to suppose that's the case with Krauthammer (and good reason to suppose it's not), but the measure itself doesn't quite indicate intelligence.

Yes, I realize that and I pointed out that this was just one component of the Weschler test. I don't really believe Krauthammer is the smartest man in the world!

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