Singapore's IQ distribution and giftedness

I have just re-read my post on Ainan going to Raffles Institution, yesterday and, on doing so, I realized that I had made an error in my analysis. I have underestimated the number of gifted students who would be at Raffles.

How have I done this? Well, I realize, now, that I had made the assumption, in my statement that 1 in 44 people will be moderately gifted (IQ 130 or more), that the distribution was a normal one about an IQ of 100: as is the standard model of IQ. So, this is right, right? Wrong.

You see, the mean IQ in Singapore is, according to IQ and the Wealth of Nations (2002), 104, NOT 100. This means that the distribution of IQs in Singapore is significantly skewed towards the gifted range. Quite simply, there will be more gifted students in the Singaporean population, for its size, than there would be in many other populations of the same size. That is the number of gifted students, per head of population should be higher in Singapore, than many other countries. For instance, the mean IQ of the United Kingdom is 100; that of the United States is 98. Singapore will have notably more gifted students per head of population than these two nations - because a few IQ points shift - amounting to almost half a standard deviation, in relation to the US, will push many more students into the gifted range. This analysis assumes that the shape of the distribution is the same - a normal curve (though in fact it should be trimodal - but normal is the usual model) - about an IQ mean of 104.

(Of course, although Singapore will have more gifted students per head of population than many other nations - including the US and the UK - these nations will have many more gifted students in terms of actual numbers - because they are much larger populations.)

Applying this to Raffles Institution, without detailed analysis, gives me the sense that it is probable that ALL their students are gifted - for they are the top 3% of a population with mean IQ 104, not the top 3% of a population of mean IQ 100, as I had inadvertently assumed.

Not all nations have lower IQs than Singapore. Hong Kong, for instance, has a mean IQ of 107 - indicating that China may become real competition for the West in the future - but that is another story.