National IQ test

What is the importance of a national IQ test? Let’s first start by defining what IQ is. IQ, or the Intelligence Quotient, is a score which attempts to quantity one’s intellectual or cognitive abilities. At its origins, IQ was calculated as the ratio of Mental Age (MA) divided by the person’s Chronological Age (CA). Although this equation was beautiful in its simplicity (determining someone’s age is very easy!), establishing a robust expectation of MA should look like for people of different age groups was the hard part. Establishing a robust Mental Age (MA) scale would become an ipsative benchmarking process in which the test developer identified mean scores on a series of mental tasks that could be expected to be achieved by people of the same age. Naturally, you would expect eight year olds to be able to achieve more than say, five year-olds on the same mental tasks. Once test developers established the MA benchmark for every age group, calculating IQ was easy as you divided an individual’s MA by that person’s Chronological Age (CA). If the test taker exhibited advanced mental capabilities for his or her age (i.e. performance beyond their years), then that test taker’s IQ ratio would be greater than 1. Multiplying this score by 100 would yield an IQ score where 100 was the average (corresponding to your mental ability being consistent for a person of your age). For example, an eight year old (CA=8) that is able to perform mental tasks corresponding to the average 10 year old (MA=10), would have an IQ of MA/CA = 10 / 8 = 1.25 x 100 = 125 IQ.

When this initial testing methodology was first developed in the late 1800s, the scale of MAs that were established by Frenchman Binet would have reflected a national MA scale relating Parisian children which is akin to saying that his IQ scale was a Parisian IQ test rather than a French National IQ test (that is, it is now well-observed in the academic literature that people living in urban centers will, on average, have higher IQs). But the real problem with the MA/CA technique is that MA reaches full adult maturity when people reach the age of 16, and this creates problems for older adults on the same IQ scale. A 40 year old could well have an MA of 16, which would imply an IQ of 40/16 = 2.5 x 100 = 250. Clearly, this would not make any sense.

IQ tests and national IQ tests have now come a long way and the calculation of IQ scores is no longer dependent on the MA/CA equation. The calculation of IQ has changed, but the principles underpinning IQ scales have not changed fundamentally. That is, IQ scores are now calculated using standard scores (think normal distribution which can be described using mean and standard deviation) which eliminate the problem highlighted above for older adults. But the process employed by test developers of establishing average performance for various age groups remains largely the same. That is, as in the case of establishing the MA scale, test developers need to be able to establish the mean performance of a group of individuals of a certain age on a given test. To do this properly, you need a truly representative random sample of people of the country – for each age group- for which you are trying to establish a national IQ test scale.

National IQ tests in a global world?

So why the emphasis on a national IQ test? Taking a National IQ tests implies that you are being benchmarked against people of your home country. Why not other countries? Well, the literature has now clearly established that mean IQ scores and average cognitive abilities vary by country. The differences can be substantial. For instance, Americans and Canadians may well achieve very similar average score on the same IQ test, but assuming that the test is ‘culture fair’ the average person from Hong Kong would be able to score more highly than his or her North American counterparts on that same test. So if you have a Hong Kong national taking a US test, her IQ score and percentile (i.e. performance against the average) is likely to be over inflated compared to what it would have been if that same person had taken a ‘Hong Kong national IQ test’. This is so because the mean scores in Hong Kong would be higher than the mean score on Canadian or American tests.

This is why the concept of a national IQ test can be relevant. But in the internet age and in terms of online IQ tests, it is important to recognize that many markets are now global and boundaries meaningless. You are no longer competing solely against your country men and women. So the importance of a national IQ test is in fact falling. But I would argue that if you are serious about understanding your own intellectual abilities, you should be interested in knowing how you fare not only on a national IQ test relative to your own countrymen and women, but also on a global IQ test where people like you and me congregate online.

At we have established three scientific culture-fair IQ tests and we are building a database of national IQs by country as seen here. Because our site is relatively new, we do not yet have a sufficiently large number of observations for all countries to be able to derive accurate statistics for national IQs. We expect IQ ranges for the various countries to normalize over time as the number of observations increase. That said, the basic scoring scale on the individual IQ tests that we offer is not inconsistent with that which is used by Mensa in the USA and in several European countries. We are confident that our IQ tests will provide you with an accurate estimate of your fluid intelligence (Gf).

To try our culture-fair IQ test, click here.