August 21, 2004

Richard Lynn's Massaged IQ Data

Anyone who uses Richard Lynn's national IQ values should be aware that this data is "massaged"; either that, or Lynn doesn't know elementary arithmetic. Of course, I did not have time to go through all of the studies referenced by Lynn, so I manually checked his reported numbers from Buj (1981), a study on national European IQ levels, which I have personally read when writing my Greek and European IQ page.

The first column below are the original numbers from Buj (1981) taken from [1] and cross-checked against my own reading of the original paper. The second column are the numbers reported in IQ and the Wealth of Nations. Lynn rounds most numbers to the closest integer, but Italy's score is rounded down (0.8->0), Austria's score is rounded down (0.5->0), Ireland's score is "rounded" up (0.2->1), Norway's score is 1.8 lower than the real one, Greece's score is 2.4 lower than the one reported by Buj (1981). All in all, 5 errors in 19 numbers from a single study.

Holland 109.4 109 rounded
Germany 109.3 109 rounded
Poland 108.3 108 rounded
Sweden 105.8 106 rounded
Italy 103.8 103 truncated
Austria 103.5 103 truncated
Switzerland 102.8 103 rounded
Portugal 102.6 103 rounded
Norway 101.8 100 -1.8
Denmark 100.7 101 rounded
Hungary 100.5 101 rounded
Czechoslovakia 100.4 100 rounded
Spain 100.3 100 rounded
Belgium 99.7 100 rounded
Greece 99.4 97 -2.4
Ireland 99.2 100 +0.8
Finland 98.1 98 rounded
Bulgaria 96.3 96 rounded
France 96.1 96 rounded


Buj, V., 1981, Average IQ values in various European countries, Personality and Individual Differences, 2, 168-169.


Unknown said...

These differences are not significant and do not affect any of Lynn's conclusions...

Unknown said...

No, but they damage his credibility, which might affect our conclusions about his conclusions.