Note: An earlier version of this article contained speculative data about how scaled scores related to IQ on the original WAIS. I have since been provided with the correct numbers and so this article was substantially revised on March 16, 2016.
As I’ve discussed before, a commenter named Andrew informed of me this study, where six samples of seniors from the extremely prestigious Dartmouth (the 12th most selective university in America) averaged 1357 on the pre-1974 SAT. I previously estimated that 1357 before 1974 equaled IQ 133 (U.S. norms); 132 (U.S. white norms). However because many Ivy League students presumably took the SAT multiple times and only their best scores are counted, it’s reasonable to deduct the equivalent of 2 IQ points from these SAT derived IQ equivalents, reducing them to 131 (U.S. norms), 130 (U.S. white norms).
Assuming these students are typical of high SAT Americans, it is interesting to ask how much they regress to the mean on various subtests of the WAIS.
Averaging all six samples together, and then adjusting for the yearly Flynn effect from the 1950s through the 1970s (see page 240 of Are We Getting Smarter?) since the WAIS was normed circa 1953.5 but the students were tested circa 1971.5, then converting subtest scaled scores to IQ equivalents, in both U.S. norms and U.S. white norms (the 1953.5 norming of the WAIS included only whites), we get the following:
|iq equivalent (u.s. norms)||iq equivalent (u.s. white norms)||estimated correlation with sat in the general u.s. population inferred from regression to the mean from SAT IQ 31 points above U.S. mean.|
|sat score||131||130||31/31 = 1.0|
|wais information||128.29||127.2||28.29/31 = 0.91|
|wais comprehension||122.22||120.9||22.22/31 = 0.72|
|wais arithmetic||120.37||119||20.37/31 = 0.66|
|wais similarities||119.16||117.75||19.16/31 = 0.62|
|wais digit span||117.37||115.9||17.37/31 = 0.56|
|wais vocabulary||125.93||124.75||25.93/31 = 0.84|
|wais picture completion||105.87||104||5.87/31 = 0.19|
|wais block design||121.82||120.5||21.82/31 = 0.7|
|wais picture arrangement||108.33||106.55||8.33/31 = 0.27|
|wais object assembly||113.65||112.05||13.65/31 = 0.44|
|wais verbal scale||126||125||26/31 = 0.84|
|wais performance scale||116||114||16/31 = 0.52|
|wais full-scale||123||122||23/31 = 0.74|
Information and Vocabulary have the strongest correlation with SAT
Of all the individual subtests, Information correlates most with SAT scores, followed by Vocabulary. This makes sense because Information (a test of general knowledge), like the SAT. measures verbal and numerical acquired knowledge, and Vocabulary, like the verbal SAT, measures verbal acquired knowledge. Also, Information and Vocabulary are highly g loaded, and should correlate well with all tests.
It is interesting that two commenters on this blog with extremely high SAT scores have reported very high scores on these subtests. Black national merit finalist ruhkukah obtained his two best WAIS-IV scores on Information and Vocabulary (both at the 99.9 percentile, and even this might be an underestimate because this is the ceiling of these subtests).
Meanwhile commenter chartreuse, who scored 1560 on a version of the SAT, and perfect on the GRE (which is very similar to the SAT) notes that his highest Wechsler subtest score from childhood was on Vocabulary. He did not state his Wechsler Information score, but did report performing twice his chronological age on another general knowledge test from childhood.