The graph below shows the distribution of IQ throughout the population. IQ tests are normed so that the average IQ is 100 and the standard deviation is 15 (or for some IQ tests, it’s slightly different) You can see from the graph that about 68% of the population (slightly over 2/3) have IQ between 85 and 115. Only about 2.4% are gifted (IQ over 130) and only 2.4% mentally challenged (IQ < 70).
However, if we were to test all the people who have a net worth of more than $1,000,000, we would probably get a distribution that is similar to the bell curve above, but shifted to the right about 10 to 15 IQ points. This means that about 2/3 of these people with net worth $1,000,000 or more would have IQ between 100 and 130, but about 16% of them would have IQ < 100. That is, about one in six of these people would have an IQ that is below average.
At the other end of the curve, there might be about one in six of these high net worth people who are of IQ 130 or higher. This would include some of the billionaires like Elon Musk, Jeff Bezos and Bill Gates It would also include a lot of the quants and investment gurus like Bill Simon, as well as many brilliant people in academe who specialize in the STEM subjects. Even though many very intelligent people don’t pursue the accumulation of wealth, they tend to be responsible with money and during their lives acquire a home and investments that push their net worth well beyond the million-dollar threshold. Such people were profiled in the 1997 bestselling book The Millionaire Next Door by Stanley and Danko.
I don’t know of a comprehensive nation-wide study that has administered IQ tests to only those of net worth more than a million dollars, so the “second graph” proposed above is merely an educated guess based on correlations between IQ and wealth. The actual graph of the IQ distribution among those of net worth greater than $1,000,000 might not form a perfect bell curve or may be shifted a little more or less than proposed. However, the “take-home” message is that there is a wide range of intelligence among the wealthy. Some wealthy people are not very bright and some are brilliant. Most of them are more intelligent than average and the super-wealthy self-made billionaires usually combine a high IQ with passion, intensity of purpose and a strong work ethic. However, it is quite possible to meet someone of high net worth who would not score well on an IQ test.
