More stuff about global IQ from various far right sources which I shan’t bother linking to. This a sort of whine about how the OECD’s PISA study of 15 year olds in several educational areas gets positive coverage but noted IQ nut Richard Lynn’s claims about global IQ don’t.
The reasons are straight forward but ignored by Vox Day et al who like to make use of global IQ claims to push their racist theories:
- These supposed global IQ studies are based on pulling together multiple data sets largely not designed for cross-national study.
- IQ tests themselves in general are not designed for this kind of study.
- IQ and IQ scores are based on core assumptions about how the trait is distributed across the population (e.g. an IQ score is directly related to the standard deviation of the target population).
- The samples for the data sets were chosen for the purpose of whatever the original study was and not for cross national comparisons.
Compare that with PISA.
- The tests are designed for the express purpose of cross national study. That involves extensive trialing of the test questions as well a heavily moderated translation process to try and ensure the people taking the tests are doing equivalent questions.
- The sample size per country are chosen to be at LEAST big enough to allow for cross national comparisons and are often larger per country to allow for internal comparisons.
- The scores are based on a completely different statistical model that makes fewer assumptions about the distribution.
Now having said all that there are still plenty of reasons to be skeptical about PISA rankings and comparisons. However, global IQ claims are necessarily WEAKER methodologically and statistically than PISA scores. Of the two, the PISA scores are far more sound and without some substantial evidence to the contrary, the PISA data trumps Lynn’s number fudging.
Fine to disbelieve both but if you have to pick PISA is far, far, far more sound.