The Idiocy of the Average - and Why It Matters

Reasonably intelligent people (for instance, the readers of this blog) tend to overestimate how smart everyone else is. About half of Americans are unable to correctly read a table and do a simple addition/subtraction calculation. Such is the banal reality of the American high-90s average IQ, which is still a dozen points above the world average.

You might have a good general appreciation of the different average IQs of the world’s major regions and appreciate that national wealth depends largely on a population’s intelligence, but putting the two together is quite tricky.

PISA website has sample math questions from the 2012 assessment, with six different levels of difficulty. Hopefully, this will give us a better perspective on what average national IQ means in practice. And why seemingly minor differences between them are important and explain the vast bulk of international differences in GDP per capita and general socio-economic success.

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Level 6

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I suspect that many of you can do it in your heads within a minute. But a majority of all the tested teens begged to differ.

OECD average: 3% (!!). Korea: 12%, Japan: 8%, Germany: 5%. The US, Italy, Sweden, and Russia were all at 2%; the Mediterranean was at 1%.

Some countries where a big fat 100% (rounded up) were unable to do this problem: Argentina, Brazil, Chile, Colombia, Indonesia, Jordan, Kazakhstan, Malaysia, Mexico, Peru, Qatar, Tunisia, Uruguay.

The number of people at this level, the highest measured by PISA, is dwindling away into insignificance in Latin America and the Middle East.

According to Kremer/Jones, it is the relative strength of the O-Ring sector in the developed world which explains why a hairdresser earns five times as much in Belgium as in Brazil. Why is this O-Ring stronger in Belgium than in Brazil? Because in Brazil, only a tiny fraction of high school students can do anything much more complex than a simple, single-step arithmetic operation.