The stupid rich and poor smart do exist

By Razib Khan | January 21, 2011 12:56 am

WORDSUM is a variable in the General Social Survey. It is a 10 word vocabulary test. A score of 10 is perfect. A score of 0 means you didn’t know any of the vocabulary words. WORDSUM has a correlation of 0.71 with general intelligence. In other words, variation of WORDSUM can explain 50% of the variation of general intelligence. To the left is a distribution of WORDSUM results from the 2000s. As you can see, a score of 7 is modal. In the treatment below I will label 0-4 “Dumb,” 5-7 “Not Dumb,” and 8-10 “Smart.” Who says I’m not charitable? You also probably know that general intelligence has some correlation with income and wealth. But to what extent? One way you can look at this is inspecting the SEI variable in the GSS, which combines both monetary and non-monetary status and achievement, and see how it relates to WORDSUM. The correlation is 0.38. It’s there, but not that strong.

To further explore the issue I want to focus on two GSS variables, WEALTH and INCOME. WEALTH was asked in 2006, and it has a lot of categories of interest. INCOME has been asked a since 1974, but unfortunately its highest category is $25,000 and more, so there’s not much information at the non-low end of the scale (at least in current dollar values).

Below you see WEALTH crossed with WORDSUM. I’ve presented columns and rows adding up to 100%. Then you see INCOME crossed with WORDSUM. I’ve just created two categories, low, and non-low (less than $25,000 and more). Additionally, since the sample sizes were large I constrained to those 50 years and older for INCOME.

Wealth & Intelligence (2006)
Columns = 100%
Less than $40 K$40-$100 K$100-$250 K$250-$500 KMore than $500 K
Not Dumb5565635748
Row = 100%
Less than $40 K$40-$100 K$100-$250 K$250-$500 KMore than $500 K
Not Dumb3216241810
Income & intelligence (2000-2008), age 50 and above

Columns = 100%
LowNot Low
Not Dumb5050
Row = 100%
LowNot Low
Not Dumb3268

Of those with low income, about 1 out of 5 are smart. And of those who are smart, 1 out of 5 are poor. Remember, this is for those above the age of 50, not college students. I thought perhaps retirees might be skewing this. Constraining it to 50-64 changes the results some in a significant fashion. 1 out of 5 poor remain smart, but only 1 out of 10 of the smart are poor. As for the rich dumb, you have to look to wealth. It is notable to me that there’s a big drop off at more than $500,000 dollars in wealth. And, a large fraction of those with wealth in the $100,000 to $500,000 are dumb. I think we might be seeing the 2000s real estate boom.

In any case, I began to think of this after a recent post by the quant-blogger Audacious Epigone, Average IQ by occupation (estimated from median income). This is what he did:

…It’s not supposed to be an exact measure of IQ by profession by any means, as it is based entirely on average annual income figures. In other words, it’s an income table with the values converted to IQ scores….

…the following table estimates average IQ scores by occupation solely on the basis of the Career Cast mid-level income figures. The median salary (of a paralegal assistant) is taken to correspond to an IQ of 100. One standard deviation is assumed to be 15 IQ points….

You can see the full list at the Audacious Epigone‘s place, but here’s a selection I found of interest:

OccupationEstimated IQ from median income
Petroleum engineer126
Financial planner123
Nuclear engineer121
Aerospace engineer120
Software engineer117
School principle116
Electrical engineer115
Web developer115
Construction foreman115
Mechanical engineer113
Registered nurse107
Police officer101
Social worker97
Nuclear decontamination technician96
Bus driver95
Agricultural scientist95
Travel Agent93

Off the top of my head, I would say that the highest disjunction in the low income direction would be clergy. This is especially true for Roman Catholic and mainline Protestant denominations in the United States, which have moderately stringent educational prerequisites for their clerics. I assume that the biggest in the other direction are surgeons and medical doctors, who enter a market where there’s less and less real price signalling, where labor controls the supply of future labor, as well as well influencing the range of services that competitive professions (e.g., nurses) can provide.


Comments (18)

  1. vg

    An undertaker is smarter than an archaeologist. Hah! And what’s an agricultural scientist? A farmer with a college degree? They don’t seem to be very smart or earning much.

  2. AG

    Agree. There are small number of surgeons who thought neoplasm only cancer and clean surgical resection as treatment of lymphoma. These surgeons have been reduced to simple operators without much medical knowlage in their heads any more. Yet, they still make big bucks.

    Certainly majority of surgeons are brilliant despite of those stupid outliers.

    (FYI, neoplams include both benign and malignant tumors. Lymphoma is whole body disease which should be treated with chemotherapy and radiation).

  3. I wonder what the test-retest correlation on wordsum is? I mean, it’s 10 words as part of a much bigger survey. I guess a lot of people could just goof up, if they’re having a bad day or got distracted on that part of the survey.

    Surveys typically find 5-10% give totally imbecilic answers, when offered the choice. I wonder if that truly reflects the number of imbeciles in the world.

  4. Jason Malloy

    INCOME has been asked a since 1974, but unfortunately its highest category is $25,000 and more, so there’s not much information at the non-low end of the scale (at least in current dollar values).

    REALRINC is the inflation adjusted income variable.

    (Also CONRINC)

  5. AG

    Here is academic measurement of IQ/profession.

    Compare to Audacious Epigone Average IQ by occupation (estimated from median income) listed above by Razib.

    Obviously quite a lot of occupations do not deserve what they get.

    On the other hand, not all smart people want to become surgeons or physicians. So income is only correlated with IQ but not equal to IQ.

  6. marcel

    And of those who are smart, 1 out of 5 are smart..

    I see. So, 80% of those who are smart are not smart? I really don’t feel comfortable with logic that does not rely on the law of the excluded middle. Perhaps you could restate this in other terms that are more easy to interpret. Perhaps you meant, “And of those who think they are smart, 1 out of 5 are smart.” This would fit the world that I know and experience every day, though how you get that from these numbers is not clear to me.

    Perhaps I’m being too smart (or too cute)?

  7. Richard D. Morey

    “In other words, 50% of the variation of WORDSUM can explain 50% of the variation of general intelligence.” should read “In other words, the variation of WORDSUM can explain 50% of the variation of general intelligence.”

  8. Viadd

    || An undertaker is smarter than an archaeologist. Hah!

    Look at their success rates at the same task. They are both trying to dig a hole with a body at the bottom: an archaeologist might get it right one time in a hundred, but the undertaker does it every time.

  9. richard, thanks. marcel, i shouldn’t write fast before i go to sleep. but can’t resist the temptation. is that smart or dumb? 🙂

  10. Obviously quite a lot of occupations do not deserve what they get.

    deserve is a loaded word. i mean, why do morticians make good money? no one wants to do their job. that is not the case with some professions which have high credentialing barriers, and those barriers are controlled by the professionals themselves. the key is this: are there great marginal returns for having a pool of dentists who score above a particular score the DAT? i doubt it.

  11. crf

    || In other words, of the variation of WORDSUM can explain 50% of the variation of general intelligence ~~ Razib

    Still not right. Remove the first “of”.

  12. Sandi

    Of the many veterinarians (115) I’ve known, their income (or wealth) had very little correlation to their intellect. Unlike other healthcare professionals, they must generally fill the roles of physician (161), surgeon (234), pathologist (not listed), pharmacist (126), CEO (148), dentist (140), ophthalmologist (not listed), anesthesiologist (not listed), dietitian (102), physiologist (102), physical therapist (not listed), and radiologist (not listed). They must be competent in each these requirements–not just for a single species as in human medicine–but for a wide variety of species. And, they must be able to diagnose and treat without the aid of the verbal language that a human patient can provide. The fact that they are willing to do all of this for a fraction of what they could earn in many of the component professions listed is a testament that either they do what they do out of love, or that it is possible to have great intellect and still be pretty dumb.

  13. I’d be curious to know if there was a sex bias in the GSS data, particularly in the over 50 age group. The prevailing meme is that assortive marriage is becoming more common, and hence may not have been as common in the over 50 group as it is today.

    If that meme is correct, one would expect more affluent but not smart women than men in that age group than in the sample overall.

  14. Christopher M

    I’m not a statistician, but it seems like the results here might be skewed if the correlation between WORDSUM and IQ were different for populations at different income/wealth levels. What if, say, poorer people don’t tend to learn as many words per IQ point as wealthier people do? I’m not, of course, saying that I know that to be true.

  15. The probability of someone having an IQ of above 220 is around 1 in 10 quadrillion (10^16 – my statistical software couldn’t handle an IQ of 234 – it gave a probability of zero). It seems there are more surgeons than this probability suggests. The same problem applies to physicians (although not as seriously).

    I expect this is a result of incomes not being normally distributed.

  16. Chris T

    I wonder what fraction of ‘smart poor’ have underlying psychological conditions. Intelligence can help you compensate, but not completely.

  17. John Emerson

    Less than $40k is not poor. The American standard of living is very high, and there’s a point of diminishing returns for consumption. A lot of people make their livings one way or another and then devote their real energies to something not lucrative. Someone with a fascination with logic systems will go into IT type stuff and make tons of money. An equally smart person with a fascination with dead languages might make no money at all from it.

  18. @12. Sandi:

    We mainly do it out of love. Sometimes I realize how dumb and futile it all is in the grand scheme of the universe, so at least we’re not naïve. 🙂


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About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at


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