Per country, the median of scores (expressed in protonorms) across a large number of high-range I.Q. tests is computed. Countries are ranked by median protonorm, and then by number of scores (n).
| Rank | Country | n | med. prot. | I.Q. (σ = 15) |
|---|---|---|---|---|
| 1 | Cambodia | 6 | 500.0 | 156 |
| 2 | Slovenia | 3 | 500.0 | 156 |
| 3 | Korea_South | 2 | 480.5 | 152 |
| 4 | Russia | 2 | 480.0 | 152 |
| 5 | Serbia | 5 | 473.0 | 151 |
| 6 | Germany | 72 | 461.0 | 150 |
| 7 | Switzerland | 11 | 461.0 | 150 |
| 8 | Denmark | 16 | 456.5 | 148 |
| 9 | Belgium | 65 | 453.0 | 147 |
| 10 | Malta | 15 | 453.0 | 147 |
| 11 | Canada | 71 | 447.0 | 146.2 |
| 12 | Poland | 20 | 446.5 | 146.2 |
| 13 | Austria | 6 | 446.5 | 146.2 |
| 14 | Portugal | 25 | 440.0 | 145 |
| 15 | Cyprus | 4 | 439.5 | 144.5 |
| 16 | Iceland | 2 | 439.5 | 144.5 |
| 17 | China | 2 | 438.5 | 144 |
| 18 | Bulgaria | 4 | 434.5 | 144 |
| 19 | United_Kingdom | 93 | 433.0 | 143 |
| 20 | India | 10 | 433.0 | 143 |
| 21.5 | Norway | 29 | 428.0 | 142 |
| 21.5 | Spain | 29 | 428.0 | 142 |
| 23 | Czech_Republic | 4 | 422.5 | 141 |
| 24 | Australia | 35 | 420.0 | 141 |
| 25 | Iran | 3 | 418.0 | 141 |
| 26 | Finland | 111 | 415.0 | 140 |
| 27 | Sweden | 103 | 413.0 | 140 |
| 28 | France | 49 | 413.0 | 140 |
| 29 | Brazil | 14 | 413.0 | 140 |
| 30 | Mexico | 5 | 413.0 | 140 |
| 31 | Luxembourg | 3 | 412.0 | 139 |
| 32 | United_States | 470 | 400.0 | 138 |
| 33 | Greece | 61 | 393.0 | 137 |
| 34 | Italy | 31 | 393.0 | 137 |
| 35 | Thailand | 5 | 393.0 | 137 |
| 36 | Yugoslavia | 3 | 393.0 | 137 |
| 37 | Netherlands | 156 | 387.0 | 135 |
| 38 | Israel | 11 | 387.0 | 135 |
| 39 | Hong_Kong | 9 | 385.0 | 134 |
| 40 | Bosnia_and_Herzegovina | 7 | 375.0 | 132 |
| 41 | New_Zealand | 6 | 374.0 | 132 |
| 42 | Japan | 8 | 367.0 | 131 |
| 43 | Argentina | 3 | 367.0 | 131 |
| 44 | Philippines | 7 | 364.0 | 130 |
| 45 | Turkey | 30 | 363.5 | 130 |
| 46 | Chile | 3 | 345.0 | 129 |
| 47 | South_Africa | 13 | 343.0 | 129 |
| 48 | Lithuania | 4 | 340.5 | 128 |
| 49 | Singapore | 12 | 293.5 | 119.5 |
Total n = 1658
Most of the country names hyper-refer to images of those countries' stamps; these are scans of stamps actually received in correspondence with test candidates from the countries in question, in many cases in the period before Internet and e-mail become dominant.
[Old versions of this report - More statistical reports on intelligence tests]