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The Flynn Effect for Different Countries

Below are the rates of IQ gain per year for different locations as found by James R. Flynn in Massive IQ Gains in 14 Nations: What IQ Tests Really Measure, Psychological Bulletin, 1987, Vol. 101, No. 2, pp. 171-191. The tables are adapted from Table 15 of that paper.

In culturally reduced (non-verbal) tests there is minimal reliance on learned content. Other tests only assess verbal (learned) IQ.  But the most famous tests examine both.  For example, the Wechsler tests have both a ‘Performance’ scale and a ‘Verbal’ scale . Flynn found the highest gains in the culturally reduced tests. The lowest gains were in verbal tests. Intermediate gains were seen in mixed tests such as the Wechsler and Binet, and in these tests, the performance side had the higher gains.


In the following book various authors offer hypotheses to explain the Flynn Effect:


The first table below is a selection of columns from the table as Flynn gave it: grouped by type of test. As was just mentioned, the different types of tests give different magnitudes of gain, so countries are best compared within that context. But because some people will likely be interested in straight comparison between all the countries, a second ungrouped ranking is given. I added the "type of test" column in both tables.

A few things to note:

1) The data from some countries are more tentative than others. It is best to get a full explanation of this from the paper.
2) The data only compares countries in terms of IQ gain and so one must not draw hasty conclusions. It does not say where they started from so how can you determine who is leading? One exception is the Japan/US data on the performance scale of the WISC. Since the performance subtests of the US WISC were "essentially unaltered in the Japanese version", one can compare apples to apples. Over 1951 to 1971, the Japanese gains were 7.2 points higher than the US gains.  If you are interested in seeing proper comparisions of the average IQs of various countries, click here.
3) The data are given on a 15 point Standard Deviation Scale.

IQ Gains: Locations Grouped by Type of Test and Ranked by Rate of Gain

Location
Test
Type of Test
Rate
Leipzig, East Germany
Ravens
Culturally Reduced
1.250
France
Ravens
Culturally Reduced
1.005
Belgium
Ravens
Culturally Reduced
0.794
Belgium
Shapes
Culturally Reduced
0.716
Netherlands
Ravens
Culturally Reduced
0.667
Norway
Matrices
Culturally Reduced
0.629
West Germany
Horn-Ravens
Culturally Reduced
0.588
Australia
Jenkins
Culturally Reduced
0.490
Edmonton, Alberta, Canada
Ravens
Culturally Reduced
0.402
Australia
Ravens
Culturally Reduced
0.337
Norway
Matrices
Culturally Reduced
0.217
Great Britain
Ravens
Culturally Reduced
0.189
Great Britain
Ravens
Culturally Reduced
0.181
Japan
Wechsler
Mixed
0.835
Vienna, Austria
Wechsler
Mixed
0.824
West Germany
Wechsler
Mixed
0.741
Zurich, Switzerland
Wechsler
Mixed
0.652
Edmonton, Alberta, Canada
CTMM
Mixed
0.525
France
Wechsler
Mixed
0.380
United States
Wechsler-Binet
Mixed
0.300
United States
Wechsler
Mixed
0.243
Solothurn, Switzerland
Wechsler
Mixed
0.186
Saskatchewan, Canada
Otis
Verbal
0.628
Norway
Verbal-Math
Verbal
0.582
Belgium
Verbal-Math
Verbal
0.408
France
Verbal-Math
Verbal
0.374
Saskatchewan, Canada
Otis
Verbal
0.348
New Zealand
Otis
Verbal
0.242
Norway
Verbal-Math
Verbal
-0.133
 

IQ Gains: Locations Ranked by Rate of Gain

Location
Test
Type of Test
Rate
Leipzig, East Germany
Ravens
Culturally Reduced
1.250
France
Ravens
Culturally Reduced
1.005
Japan
Wechsler
Mixed
0.835
Vienna, Austria
Wechsler
Mixed
0.824
Belgium
Ravens
Culturally Reduced
0.794
West Germany
Wechsler
Mixed
0.741
Belgium
Shapes
Culturally Reduced
0.716
Netherlands
Ravens
Culturally Reduced
0.667
Zurich, Switzerland
Wechsler
Mixed
0.652
Norway
Matrices
Culturally Reduced
0.629
Saskatchewan, Canada
Otis
Verbal
0.628
West Germany
Horn-Ravens
Culturally Reduced
0.588
Norway
Verbal-Math
Verbal
0.582
Edmonton, Alberta, Canada
CTMM
Mixed
0.525
Australia
Jenkins
Culturally Reduced
0.490
Belgium
Verbal-Math
Verbal
0.408
Edmonton, Alberta, Canada
Ravens
Culturally Reduced
0.402
France
Wechsler
Mixed
0.380
France
Verbal-Math
Verbal
0.374
Saskatchewan, Canada
Otis
Verbal
0.348
Australia
Ravens
Culturally Reduced
0.337
United States
Wechsler-Binet
Mixed
0.300
United States
Wechsler
Mixed
0.243
New Zealand
Otis
Verbal
0.242
Norway
Matrices
Culturally Reduced
0.217
Great Britain
Ravens
Culturally Reduced
0.189
Solothurn, Switzerland
Wechsler
Mixed
0.186
Great Britain
Ravens
Culturally Reduced
0.181
Norway
Verbal-Math
Verbal
-0.133

A Commentary on the Flynn Effect and Other Points:

From what I have read in the scholarly literature, nobody denies that the Flynn Effect exists. Throughout the world, data has shown that it is almost invariable that modern generations do better on old IQ tests than earlier generations did. Although the Flynn Effect continues to be surrounded by, and is central to several controversies (for example, about the meaning of IQ, or g, or the validity of IQ tests, or how the Flynn Effect can be explained) the Flynn Effect itself has survived all scepticism.

James R. Flynn himself was perplexed by his findings (and he questioned the validity of IQ tests). He was the one who brought up the rhetorical ploy of suggesting something to the effect of that if IQs have been increasing by 3 points per decade, the ancient Greeks must have been retarded to an absurd degree. One point that Flynn and others gloss over is that there is no evidence, and no one is claiming that these IQ gains have existed forever. Indeed, one of the theories that probably explains much of the IQ gains is Richard Lynn's Nutrition Hypothesis (The Role of Nutrition in Secular Increases in Intelligence, Personality & Individual Differences Vol. 11, No. 3, pp. 273-285, 1990). Lynn claims that nutrition improvements would explain both the increases in height and in intelligence. In the above paper Lynn wrote:

For the last 2000 yr data on heights of adult males in Britain have been collected... The broad trend is that height has been constant at a mean of approx. 172 cm up to the cohort born around 1930. From this date onwards height has increased. It seems reasonable to infer that brain size and intelligence were approximately stable for about 2000 yr up to around 1930 and it is only in the last half century that the increases have occurred.

By the way, doing Flynn Effect calculations is not something I invented. Flynn Effect calculations can be found in the scientific psychological literature. Hence, when you look at the Cox 300 geniuses list, you should really be looking at my Flynn Effect corrected scores and not the original IQ score estimates if you want to compare yourself to the Eminent Geniuses. If you have old IQ scores, you might want to do your own Flynn Effect calculations. I realize that these calculations shrink the pedestal that we keep the Eminent Geniuses on, but at least it should give more of you hope that you might be able to accomplish important things (as long as you are also gifted with creativity or perseverance or whatever other factors contribute to grand achievements).


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