How many people have a genius level IQ? Is it even possible to find them all and test them, if so how and where would you start looking for these rare individuals?
The problem of estimating the number of people with genius level IQ in a particular country is much easier than testing everyone. For example, suppose you wanted to estimate how many adult American males are over 6′5″ in height. You could take a large random sample of the heights of several thousand adult American males and look at the proportion that were over 6′5″ in height. If the sample is purely random, then the proportion of adult American males over 6′5″ would be the same as in the sample. You then multiply that proportion by the number of adult males in America and you have an excellent estimate.
Pearson administers WAIS IQ tests to tens of thousands of people and observes that their scores follow a distribution that closely matches the normal distribution. That is, about 95.2% of the tested population falls within two standard deviations of the average and about 2.4% score above or below that level. This means that about 2.4% of the population has IQ above 130, which is generally considered “gifted.” Therefore, multiplying the population of America by 2.4% would provide an estimate of the number of gifted people in America. For more detailed information on this procedure, visit: https://www.intelligence-and-iq.com/what-are-the-best-tests-for-measuring-your-iq/
To find these individuals, the first place to start are the universities, because entrance requirements like SATs are highly correlated to IQ tests, and many of those who have gained entry to the top US universities have already shown themselves to have high IQ. Many of the high IQ people will be found in academe, and in top positions in business and industry. Far fewer will be found in politics.
