Way back in 1932, Scotland got the IQ of all the 11 year old kids in the country, about 80,000 of them, tested. The population was made up of equal number of boys and girls. Called the Scottish Mental Survey (SMS), till this day, SMS is the largest such test carried out anywhere in the world. The test methodology and the findings of SMS have not been contested seriously till today. SMS has become the gold standard to understand the gender difference in IQ. The result of the test is plotted in the chart below.
The chart shows the number/percentage of girls of various IQ, plotted against the number/percentage of boys. Let’s see that result test implies.
- Boys and girls are equally smart. Boys had an average IQ of 100.5 and girls had an average IQ of 100.6, the difference being insignificant.
- 85% of the girls are smarter than the boys. Can you guess why the (Second Wave) feminists never used this proof to argue that women or smarter than men? Well, you must take a look at “4” below
- Lower the IQ, you will find more boys than girls. This may be one of the reasons why there are more boys with learning disability issues.
- Now, this is the kicker: Higher the IQ, you will find more boys than girls! At around IQ 140 (little above the IQ of University Professors and PhD holders), there are 35% more boys than girls. Given how smooth this curve it, if I dare extrapolating it to 160-165 range (where all the Nobel laureates loiter), we have a 65:35 boys to girls ratio! It means that at this range, there are 70% more boys than girls.
Interesting. If you have noticed the distribution, something more interesting shows up. It appears as if women the are made in an assembly line with better quality control (so, they confirm closer to the mean of 100). Whereas, men are made on an assembly line that requires some fine tuning (so, their quality is all over the chart).
I wonder why most of us never know anything about this study, even though it was conducted 80 years ago and no one has been able to find any serious flaw in it till today. My guess is, gender politics!
By the way, you can click on this link to download an academic paper, discussing the results of the Socttish Mental Survey 1932. Before you go away, please remember that IQ is not the only indicator for success in life. It doesn’t even test all types of intelligence that there is.