Saturday, January 22, 2011

Average IQ by occupation (estimated from wordsum scores)

Because it does not appear to be posted anywhere else on the web, and because it was such a tedious slog to put together (a labor like this isn't going to just sit unexposed in an excel file!), the following table shows IQ by occupation as estimated from GSS wordsum scores. The mean wordsum score for native-born whites is assumed to correspond to an IQ of 100, with a standard deviation of 15.

Sample sizes are not sufficient for statistical significance for a host of job categories (as long as the respondent pool is plural, it is included), and the usual disclaimer about a ten question vocabulary test not correlating perfectly with IQ (Razib reports an r-value of .71) applies. Women tend to do slightly better on verbal measures of intelligence, while men do better on quantitative measures of the same. Calculated from wordsum scores, women enjoy a bit less than a 2 point IQ advantage over men, so heavily female occupations like teaching are slightly overstated and heavily male occupations like those involving engineering are similarly understated. To avoid issues of English language proficiency, only those born in the US are included. Because a perfect score translates to an IQ of 128, high-end wordsum scorers encounter an artificial ceiling on their purported IQ. So, to a much lesser extent, do low-end scorers, as missing all ten items corresponds to an estimated IQ of 53. Consequently, the table is merely suggestive, not definitive or statistically rigorous:

Occupation
IQ
n
1. Mathematician
117.1
4
2. Physician
117.0
48
3. Geologist
116.7
5
4. Meteorologist
116.7
2
5. College professor
115.9
89
6. Author
115.1
58
7. Librarian
114.6
28
8. Attorney
114.5
102
9. Biologist
113.7
8
10. Optometrist
112.9
3
11. Statistician
111.4
2
12. Computer systems analyst
111.3
85
13. Judge
111.0
3
14. Psychologist
110.3
20
14. Actor
110.3
20
14. Dentist
110.3
16
14. Chemist
110.3
11
18. Museum curator
110.1
4
19. Clergyman
108.9
38
20. Pharmacist
108.7
11
21. Teacher
108.1
297
22. Agronomist
107.9
6
22. Electrical engineer
107.9
46
24. Stockbroker
107.8
31
25. Fine artist
107.4
33
26. Physical therapist
107.4
40
26. Sociologist
107.4
4
28. Economist
106.6
21
29. Mechanical engineer
106.5
35
29. Architect
106.5
26
31. Real estate agent
105.7
80
32. Commercial airline pilot
105.6
12
33. Dental hygienist
105.5
33
34. Social worker
105.0
109
35. Registered nurse
104.9
238
36. Stenographer
104.6
44
37. Government official
104.1
77
37. Insurance agent
104.1
77
37. Computer programmer
104.1
41
40. Accountant
104.1
168
41. Civil engineer
104.0
23
42. Undertaker
103.6
8
43. Jeweler
103.2
5
44. Secretary
103.1
430
45. Engineering technician
102.6
55
46. Police officer
102.5
81
47. Industrial machine repairer
102.4
9
47. Photographic process worker
102.4
6
49. Debt collector
101.7
10
50. Sales representative
101.6
134
50. Compositor/typesetter
101.6
8
52. Fashion designer
101.4
7
53. Photographer
100.8
19
54. Receptionist
100.8
104
55. Machine tool operator
100.6
7
56. Veterinarian
100.4
5
57. Communications equipment mechanic
100.2
9
57. Broadcast technician
100.2
9
59. Glazier
99.3
3
60. Mail carrier
99.1
68
61. Retail salesperson
99.0
368
62. Telephone operator
98.7
41
63. Dressmaker
98.4
18
64. Bank teller
97.8
67
65. Licensed practical nurse
97.5
73
66. Plumber
97.3
66
67. Maid
97.1
107
68. Waiter/bartender
96.5
289
69. Aircraft mechanic
96.3
21
70. Barber
96.2
117
71. Data entry clerk
96.0
53
72. Carpet and tile installer
95.8
143
72. Painter
95.8
51
74. Child care worker
95.4
181
75. Tool maker
95.3
53
76. Telephone installer/repairer
95.1
10
77. Security guard
95.0
26
78. Farmer
94.7
11
79. Bus driver
94.6
45
79. Firefighter
94.6
42
81. Insulation installer
93.9
5
82. Cashier
93.8
290
83. Furniture upholsterer
93.7
13
84. Electrician
93.6
66
85. Taxi driver
93.5
76
86. Bookbinder
93.0
5
87. Welder
92.7
63
88. Automobile mechanic
91.6
131
89. Dietitian
91.5
9
90. Truck driver
90.6
216
91. Railroad conductor
90.4
7
91. Sailor
90.4
3
93. Bricklayer
90.3
22
94. Cook
90.3
140
95. Construction worker
90.0
139
96. Roofer
89.3
16
97. Sheet metal worker
88.5
44
98. Carpenter
87.4
3
99. Janitor
86.9
82
100. Drill-press operator
86.7
2
101. Forklift operator
85.8
42
102. Butcher
84.3
21
103. Concrete worker
82.9
8
103. Surveyor
82.9
2
105. Shoe maker/cobbler
79.6
6
106. Lumberjack
75.3
8

GSS variables used: ISCO88, WORDSUM, BORN(1)

25 comments:

FuturePundit said...

These results make me skeptical of GSS wordsum as a good proxy for IQ. I have a hard time believing EEs and MEs have average IQs below 110 or even below 115. The scores of commercial airline pilots and RNs seem too low as well.

I think of La Griffe Du Lion's Smart Fraction Theory cut-off around 106 for people who contribute to a higher per capita income. Difficult jobs are above that level.

ironrailsironweights said...

Of course there's just an n=2, but there is no way in creation that a person with a score of 82.9 could function as a surveyor. And 100.4 for a veterinarian simply boggles the mind.

Peter

Audacious Epigone said...

Futurepundit,

Well, a vocabulary test is going understate the IQs of engineers (and presumably, mathematicians, despite their still being at the top of the list) more than just about any other occupation.

Perhaps you're correct, but I think we in the steveosphere (or HBD blogosphere or whatever you'd like to call it) and your overlapping but distinct futurepundit readership are way on the right end of the curve, even among colleagues of the professions we're engaged in (which are mostly white collar/professional). In the case of mechanical engineers, for example, the median wordsum test taker (born in the US), missed three of these ten words. Among physicians, half missed at least two. I'm skeptical that the average doctor or college professor does not know what the words "allusion" and "emanate" mean, but that is the reality.

Re: the smart fraction theory and RNs inclusion in it, that means fewer than 1 in 10 blacks meet the cognitive requirements to be nurses. That isn't the sense I get from what I've seen.

Peter,

Yes, those sample sizes are obviously highly unreliable. But there are surveyors out there, somewhere, born in the US, who missed half the words shown at the link to Inductivist's post where he reveals wordsum's contents.

Steve Sailer said...

Thanks.

It's a low stakes test so people probably put less effort into checking it twice, which tends to compress scores.

You might be able to estimate the impact of the restriction of range problem by looking at the 10/10 scorers for different groups to see if there are more of them than, say, 9/10 scorers.

The rank order seems pretty good, although biased against quant types by being a vocabulary test.

Jack said...

Besides the obvious low relative scoring of engineers and accountants, and high relative scoring of teachers, I noticed that cops scored a pretty significant 8 points higher than firemen. It usually seems that both groups usually are estimated at similar IQ's, so i found this interesting.

FuturePundit said...

Aud,

I think psychometricians have collected a lot of data on IQ and occupations. If you go to this PDF on page 3 you will see occupations of white enlisted men in 1945. You can also see another table on page 58 of this document by Linda Gottfredson.

But these tables lack many modern job categories. I'd like to see different engineering fields and assorted IT jobs listed.

Audacious Epigone said...

FP,

The numbers from 1945 appear to really be inflated, but I think rank order is more important than converted score. I agree with your thrust, but another source is rarely a bad thing, and since I did the legwork, I figured I might as well let everyone else take a look at it.

Jack,

Yes, I noticed that as well and almost included it in the body of the post. The sample sizes for both are sufficiently large, making it a curiosity that's not easy to just blow off as the product of randomness.

FuturePundit said...

Aud,

1945: The lower skilled occupations had smarter people in them because few of the smarter people had switched to cognitively demanding occupations yet.

Steve Sailer said...

The 1945 scores are from white enlisted men in the Air Force. I suspect the Army Air Corp got a lot of applicants and was fairly selective compared to the Army. On the other hand, Air Force officers probably scored even better on average.

Joseph said...

I suppose the table means that if you're a lumberjack, that's not okay.

Anonymous said...

sociologist > engineers

you gotta be joking

eeddy said...

> Lumberjack 75.3
That one also seems meaningless. 75 is basically retarded, and I think in general, instead of having 'simple' jobs, retarded people tend to simply not work at all, certainly not in as dangerous a field as lumberjacking.

dylan said...

How anyone could think a ten question vocabulary test shows IQ is beyond me. While my IQ is reasonably high I easily aced the wordsum test because I read a lot. Also wordsum supposedly correlates with adult IQ which is much less valid than child IQ because of education levels. It's pretty obvious for example, that people with English majors would regularly outscore people with science majors. This seems like common sense, but apparently it isn't to people that think this is an IQ test.

Unknown said...

as someone pursuing a career as a firefighter, your list is definitely inaccurate.

Matko said...

Why no philosophers on the list?

Anonymous said...

Where are the physicists?

Anonymous said...

no lawyers?

Anonymous said...

That's engineering: a bunch of pretentious morons.

Anonymous said...

Absolute garbage - Surveyors third from bottom? People who measure, manipulate and present data lower than the labourers and sales people above? Nonsense.

Huge gaps, so many other professions not mentioned. Engineers should be a lot higher up. Design Engineers that is, not people who mend washing machines.

Christopher Fornesa said...

This list does seem plausible to me since studies have shown that the average college graduate (four year university) has an IQ of around 115. Other studies show average IQ based on GMAT, GRE or other scores for entrance into master's or doctoral level programs which is fairly inaccurate since most likely, those who enter these advanced programs have developed higher capabilities and mental capacities that would allow them to even have a chance at graduate school. Those tests aren't like the SATs, the average test-taker of those particular examinations are above or around the average for college grads.

Also, IQ isn't actually a definite (or accurate) measure of intelligence or even capacity, it only measures your ability (at the time of testing) to problem solve or show how the educational system has taught you. It has little to do with skills like level of creativity and others that employers often look for in potential candidates. Although IQ can be used to measure a level of cognitive ability, saying that just because you have a high IQ, you'll be successful or because you have a lower IQ, you'll only do menial jobs, is just a sorry excuse for not working hard!

People should remember that averages are just what they are, averages. I mean if you're a male who's 5' 8" and the average is 5' 9", you're supposed to be short when the global average for males is 5' 7"? Not necessarily! Averages are only relative, from height to weight to IQ that's all that's really true about these things.

Toby Crane said...

I can not say I agree with this because my brother is studying to be an electrician and he is super smart. He just likes working with his hands. Plumbers also have great knowledge of many things. In Allentown, there is great work to be done in the plumbing industry.

Anonymous said...

Worthless chart, garbage in, garbage out.6494iticipGe

Anonymous said...

I would bet that there is a very strong association between the degree to which people commenting here think the chart is accurate and their own placement in it. Also, don't discard it because you know a guy who is an "x" and he's really super "y." That's dumb. (Personally, I trust averages more than your personal, anecdotal evidence based on an even smaller sample size and in comparison with nothing.) Finally, read. No one is saying the measure is flawless. The one reported correlation between WORDSUM and a better measure of IQ is around .7. That's a strong correlation, not a perfect one. If lumberjack were at the top, sure...there would be a massive problem. It's not. The general placement seems about right, but there do seem to be a few non-intuitive results, perhaps due to small n. Then again, maybe I should NOT trust my own, personal sense of the relationship between IQ and occupation more than this.

Anonymous said...

Some of the people I have met have been people who are not in work. They are remarkable in all areas. The only thing which I have noted is that most people who are out of work are too clever to be employed as they would be a threat to the people who give them a job, and make them look bad, or rock the boat, with better and brighter initiatives, upsetting the apple cart, for the people who think by we are paid by the hour, and not by the time and motion study. Therefore Council HR depts. will not hire unemployed people and only poach people already in employment and di not rock the boat.

Anonymous said...

http://www.sq.4mg.com/IQ-jobs.htm

Here is more accurate data from University of Wisconsin.

Better spread with standard deviation for each job.