Group IQs
[ Part of a sequence of posts on intelligence. ]
Educational Attainment
Here is a table of studies and estimated IQs by educational attainment:
| Group | Mean (SD) | Cite | Year |
| MDs or PhDs | 125 | IQ testing 101 (Table 4.3) | |
| PhD, LLD, MD, DDS | 124 | Murray | 2005-9 |
| US PhD Students | 123 | Dutton | 1958 |
| Master's degree | 117 | Murray | 2005-9 |
| 17+ years of schooling | 117 | Lichtenberger (Ch 1) | |
| 16+ years of schooling (college graduate) | 116 (12) | Lichtenberger (Table 4.5) | 1981 |
| College graduates | 115 | IQ testing 101 (Table 4.3) | |
| Bachelor's degree | 113 | Murray | 2005-9 |
| 13-15 years of schooling (some college) | 107 (11) | Lichtenberger (Table 4.5) | 1981 |
| Associate's degree | 104 | Murray | 2005-9 |
| 12 years of schooling (high school graduate) | 101 (12) | Lichtenberger (Table 4.5) | 1981 |
| High school graduates | 100 | IQ testing 101 (Table 4.3) | |
| High school diploma/GED | 99 | Murray | 2005-9 |
| 8 years of schooling (elem school graduate) | 94 (11) | Lichtenberger (Table 4.5) | 1981 |
| 8th Grade Graduates | 90 | IQ testing 101 (Table 4.3) | |
| No degree | 87 | Murray | 2005-9 |
| 0-7 years of schooling | 83 (14) | Lichtenberger (Table 4.5) | 1981 |
| 0-7 years of schooling | 81 | Lichtenberger (Ch 1) | |
| The data in tables 4.3 and 4.5 was published in 1987, but was based on data from a 1981 test Lichtenberger Reynolds. | |||
Finally, here are some simples estimates I computed based on the NLSY97 dataset NLS Investigator:
| Degree | Median |
| None | 82.5 |
| GED | 88.0 |
| High school diploma | 94.7 |
| Associate's degree | 99.1 |
| Bachelor's degree | 106.9 |
| Master's degree | 108.9 |
| PhD | 117.5 |
| Professional degree | 119.0 |
Note, these numbers here are about five points lower than the ones found by Murray despite both originating from NLSY97. At least one of the reasons is that Murray only considers whites.
Institutional Selectivity
All around the internet, you'll find extremely poor reasoning trying to estimate the average IQ at a college from its average SAT scores. The logic goes, the average SAT score of students attending College A is X. This is the Yth percentile. The Yth percentile in IQ is Z. Therefore, the average IQ at College A is Z. I'm not going to explain why this reasoning is absolutely awful, but its worth pointing out since it's so common.
We discussed IQ estimates of students at the most elite colleges in the previous post, finding that it is probably in the mid-to-upper 120s - probably just a few points higher than the known ACT/IQ and SAT/IQ correlations predict. Realistically, you'll probably find just plugging in the average ACT/SAT score at a school into those models and maybe nudging it down a couple points.
Field
Average IQ varies quite a bit by subject matter, with STEM participants generally performing better than non-STEM ones Dutton. This is generally reflected by the average SAT score of students grouped by intended major, which generally finds STEM majors score the highest, followed by humanities majors, and then more vocational degrees Table 226.30.
Jobs
Here is a table of studies and estimated IQs by occupation:
| Group | Average IQ | Cite | Year |
| "eminent American scientists" | 158 | Dutton (Table 1) | 1953 |
| Cambridge academic staff | 126 | Dutton (Table 1) | 1967 |
| Professional and Technical | 114 (12) | Lichtenberger (Table 4.5) | 1981 |
| Professional or technical | 112 | Lichtenberger (Table 1.3) | 1981 |
| Managers, Clerical, and Sales | 107 (11) | Lichtenberger (Table 4.5) | 1981 |
| Managers and administrators, clerical workers, and sales workers | 104 | Lichtenberger (Table 1.3) | 1981 |
| Skilled workers | 101 | Lichtenberger (Table 1.3) | 1981 |
| Skilled Workers | 100 (12) | Lichtenberger (Table 4.5) | 1981 |
| Semiskilled Workers | 94 (14) | Lichtenberger (Table 4.5) | 1981 |
| Semiskilled workers | 92 | Lichtenberger (Table 1.3) | 1981 |
| Unskilled Workers | 90 (15) | Lichtenberger (Table 4.5) | 1981 |
| Unskilled workers | 87 | Lichtenberger (Table 1.3) | 1981 |
And a figure:
Figure from Hauser, but I took the liberty of adding lines for IQs of 80, 90, 100, 110, and 120.