I.Q. Score Range By Occupation
First, let me be clear – I don’t put a whole lot of stock in I.Q. tests. And it’s not because I don’t score well on them; on the contrary, I do quite well on all standardized, fill-in-the-bubble type tests. However, I know many, many intelligent people who do not do well on these types of tests. For that reason, I think that most standardized tests are at least a bit flawed.
Still, I find charts mesmerizing. I like looking at them. They are shiny. :)
I ran across this chart & found it interesting.

I take at least two things away from studying this chart.
First and foremost, I challenge the accuracy of this I.Q. chart as a measure of “intelligence.” I don’t for one second believe that people working in lower scoring occupations such as “Janitors and Sextons” are less intelligent than doctors, professors, or engineers. Perhaps they are less “educated,” in the traditional sense of the term, but the path many of them chose was more a function of their upbringing than it was any natural ability. I believe that the large overlap proves this point.
Second, and most importantly, looking at this chart with uneducated janitors at one end and hyper-educated doctors at the other makes me want to just scream out “DUH!” Of course professions that require schooling and entrance exams will tend to consist of individuals who do better in school and on entrance exams.
It’s as if I wanted to set up a chart for measuring athletic ability and used only the 100 meter dash and a handful of other events as the measuring stick. By that standard, not only is Usain Bolt (the fastest man in the world) the best athlete in the world, but Michael Jordan, Tiger Woods, Wayne Gretzky, and Brett Favre are not just also-rans, but “never-rans.”
A dubious system indeed.
A Reddit.com thread on the topic.


September 17th, 2010 at 9:07 pm
You’re right that IQ can be skewed because of the type of test they made the participants take, but it’s less mathematical formula and vocabulary than discerning patterns and recognizing discrepancies. Observably, some people are born with less ability to “get” some of society’s key skills such as language, mathematics, and cognitive abilities, and I guess that’s what this graph is expounding.
January 27th, 2011 at 6:38 am
Hi, nice chart. Can you give the reference info for it? Where did you find this information because I’d be interested in reading the authors explanation for the results.
November 3rd, 2011 at 3:05 pm
IQ means “Intelligence Quotient”. It is a ratio, or a fraction, if you will. It is a measure of how much you have learned, compared to how much other people your age have learned. I was developed to put children in grades, before grade schools were started.
If you have learned 1 1/2 times what an average person has learned, your IQ is 150. It’s that simple. So, of course, those who use more data and education in their day-to-day work will most often have higher IQs.
There may be examples of janitors who know quantum mechanics, but this is the exception. There is not, however, a quantum physicist who only knows about janitorial work.
November 3rd, 2011 at 3:20 pm
You’re pretty misinformed, DR L.P. An IQ test doesn’t test knowledge, it tests reasoning ability & aptitude. The test asks virtually zero knowledge based questions. Instead, it asks the test taker to reason out the answer from the presented information. “What number comes next in this series” and “a is to b as c is to ?” have very little to do with pre-acquired knowledge.
November 17th, 2011 at 2:31 pm
[...] If anything, IQ is mostly correlated with social class. Check out this chart: [...]