The Inductivist recently used Wordsum scores from the GSS to estimate the average IQ of high school teachers by decade. Another one of the blogging world's best raised a few follow up questions and directed them to me in response, prompting a turn to the database.
Frustratingly, I wasn't able to find a variable identifying teachers (it would be optimal for all quant bloggers to adopt the practice Agnostic started and include those used at the end of a post), and lack the patience to wait for Inductivist to fill me in. The GSS does record occupational information based on the International Standard Classification of Occupations, however. ISCO has had two major revisions since its inception, the last in 1988, and varies slightly by country. After a lot of googling, I've identified codes for "teaching professionals" in the US for respondents participating from 1988 and after*.
Going this route allows for some additional insights to be gleaned. Converting Wordsum results to IQ scores under the assumption that the Wordsum mean for whites is equivalent to an IQ of 100 with a standard deviation of 15 yields an average IQ of 108.4 for all teaching professionals surveyed over the last two decades. For high school teachers, this gives an estimate about one point higher than Inductivist found. The small discrepancy is probably due in part to the inclusion of administrators among educational professionals by ISCO methodology. It is also marginally closer to what I would have guessed before having any data to go by.
The total sample size for teaching professionals is 742, allowing IQ estimates by educational level to be made. The following table shows the estimated average IQ for education professionals at the post-secondary (college and university), secondary (high school), primary and pre-primary (K-8th grade), special education (gifted and short bus), and "other teaching professionals not elsewere classified" (13% of the total, perhaps professional mentors and the like) levels:
Treating Wordsum scores as proxies for IQ scores works quite well, but it's not perfect. For one thing, a perfect score of 10 equates to a maximum IQ of 127.8. As only 3% or so of the population has an IQ of 128 or higher, this artificial ceiling does not have much of an effect most of the time when Wordsum-to-IQ conversions are made for groups of GSS respondents. However, in the case of university and college educators, it does--36.9% of those surveyed scored a 10. If this contingent averaged an IQ 2.5 SDs above the white mean rather than the presumed 1.86--which is certainly plausible--the average IQ estimate for university and college educators would be slightly north of 120, with the professorial average higher still.
The 107.4 for high school and K-8th grade teachers is not a typo--they just happen to be the same, although the curve is noticeably wider for secondary educators, with a Wordsum standard deviation of 2.08 for those at the high school level to 1.78 for K-8. Perhaps math and science teachers pull the distribution to the right while PE, art, and other soft electives teachers push it to the left?
The following table shows the same for whites only:
|Level (whites only)||IQ||N|
As expected, the white distribution essentially parallels the distribution for all educational professionals, shifted to the right a couple of points.
The response pool is not large enough to break non-whites down by educational level. The table below shows the estimated average IQ of all educational professionals by race:
The black-white gap is almost exactly one standard deviation, adhering to the fundamental law of sociology described by La Griffe du Lion. Taking into account the fact that 18.2% of white educational professionals earned a Wordsum score of 10 compared to 6.7% of non-whites, the black-white difference appears to be right where the lion would predict for it to be, small non-white sample sizes notwithstanding.
GSS variables used: ISCO88(2300-2399)(2331-2332), RACE, WORDSUM
* The GSS does not offer much help in this regard, stating only that respondent occupations from 1988 onward use ISCO-88. This instructional guide on ISCO put out by Stanford shows professional educators to be represented by codes 2310-2390 (see pg 15). This more helpful listing from the University of North Carolina breaks educational categories down to the fourth digit, and the codes match up perfectly with what the GSS returns, with the exception of a discrepancy among secondary education professionals. The UNC source shows it to be represented by 2320, while the GSS returns data for 2321 but nothing for 2320 (the fourth digit is the most arbitrarily assigned--something the Stanford guide deals with in detail). Most of the possible four digit combinations from 110 to 9999 are not used, which is why I am confident I've identified the correct educational classifications--pegging four of the five in a 100 digit range with the one exception differing only by the fourth digit is almost certainly not due to chance. The Wikipedia entry agrees with both of these sources. Further, the results have face validity not only within the educational profession, but for various other occupational categorizations as well. Still, I must add a disclaimer to what is presented above--I am only 99.9% certain that I have identified the classifications correctly.