In his excellent book A Question of Intelligence: The IQ Debate in America, former Fortune magazine editor Daniel Seligman describes what it’s like to take the WAIS-R IQ test.  One page 8-9 he writes:

When the test ended, after about ninety minutes, I went over my answers with [examiner] Stern and watched him convert them into an IQ score.  Actually, you walk away with three scores: one covering the overall verbal portion of the test (where I did quite well), one covering the performance tests (where the results were mediocre), and a weighted average that becomes your IQ.  Being still coy,  I decline to state the number on the bottom line…

I was able to determine Seligman’s scores (adjusted for old norms) on three of the six verbal subtests, and three of the five performance subtests.  By taking the sum of the three verbal scaled scores and prorating, I was able to roughly estimate Seligman’s sum of scaled scores on all six verbal subtests.  Similarly, by taking Seligman’s sum of scaled scores on three of the five performance subtests and prorating,  I was able to roughly estimate Seligman’s sum of scaled scores on all five Performance subtests.  Then by adding the prorated verbal sum to the prorated performance sum, I was able to roughly estimate Seligman’s sum of scaled scores on all 11 subtests:

Similarities (unknown)
Arithmetic (unknown)
Comprehension (unknown)
Digit Span 15.94 (age adjusted 17.94)

Sum of three known verbal unadjusted scaled scores: 47.59
Estimated sum of all six verbal unadjusted scaled scores: 95.18

Picture Completion: 5.8 (age adjusted 7.8)
Picture Arrangement (unknown)
Block Design 9.59 (age adjusted 12.59)
Object Assembly (unknown)
Digit Symbol 8.22 (age adjusted 11.29)

Sum of three known performance unadjusted scaled scores: 23.61
Estimated sum of all five performance unadjusted scaled scores: 39.35

Estimated sum of all 11 unadjusted scaled scores: 134.53

Using the WAIS-R manual, I was able to determine the verbal IQ, performance IQ, and full-scale IQ of 55-64 years with an unadjusted sum of scales scores of 95.18, 39.35, and 134.53, respectively. They are:

Verbal IQ: 146
Perfomance IQ: 100
Full-scale IQ: 128

Of course all of these figures are in U.S. norms which is what the Wechsler scales have used for the last several decades. In U.S. white norms (which the scales originally used and are still used in the technical literature), the corresponding figures are 146, 98, and 127 respectively. But it’s probably best to err on the high side because on page 9 Seligman writes:

…I discovered with some annoyance that the WAIS data are not extensive enough to make possible a precise fit for sixty-four-year-olds. It seems that in calculating my IQ score he had to think of me as belonging to the whole cohort aged fifty-five to sixty-four. This means I was being compared with sharp-witted folks in their fifties, whereas if I had taken the test six months later, after my sixty-fifth birthday, I would have been normed against dotards ranging up to sixty-nine–and my IQ would have been five points higher. I may go back for a replay.

Of course just as being the oldest in a younger cohort underestimated his IQ, being the youngest in an older cohort would overestimate IQ, so maybe split the difference and give him an extra 3 IQ points.

So now that we know Seligman’s IQ was 128+3 = 131 (U.S. norms) or 130 (U.S. white norms) it is interesting to look back at the guessing game we played before I began this series, to see who came closest.  ruhkukah said 135-140, which for the purpose of this game, I interpret as 137.5.  Konstantin said 138…but neither were as close as jameson who said in the 120s range, which for the purpose of this game, I interpret as 125.  jameson’s argument was that since Seligman writes and talks about intelligence,  he’s probably very intelligent, but not as intelligence as someone who is actually out there doing intelligent things.  Writers and talkers in a given subject are not as talented at that subject as actual doers.

Still, Seligman’s IQ was higher than 98% of white America’s, and higher than most PhDs and Ivy League undergrads, making him an extremely intelligent man.

So who’s the loser in this game?  Sadly, it’s grey enlightenment who estimated Seligman’s IQ to be 150.  grey later revised the figure downward, but once the series began and scores started being revealed, it’s too late to change your guess, but in grey’s defense, he was very close to Seligman’s verbal IQ, and since the game was to guess Seligman’s IQ based only on a sample of Seligman’s writing, his guess made a lot of sense.