Tuesday, May 1, 2018

Vox Popoli: Mailvox: expert witness (on the myth of the 115 mean IQ of Jews being pushed by Jordan Peterson)

John Fuerst of the Ulster Institute weighs in on the myth of the 115 mean IQ being pushed by Jordan Peterson, among others, with a pair of comments here:

I more or less agree with Vox. I collaborate with Richard Lynn and I am familiar with the literature and most of the studies (both reported and not).

As for Israel, on international tests, Hebrew speakers (Jews) score around the level of White Europeans, while Arab speakers score around that of other Middle Easterners (around 1+ standard deviation below the European White mean). See, for example, "Why Israel does poorly in the PISA exams – perceptions versus reality (2017)", and the Taub Centers’ “State of the nation picture (2014/2017)” reports.

For example, the non- Haredi Jewish PISA 2012 math average was 489 (SD ~93), for White Americans for the same year it was 506 (SD 83). For Israel and the US as a whole, the means and SDs were, respectively, 481 (SD 90) and 466 (SD 105).
There is year to year variability. But it is safe to say that on international math, reading, and science exams, Israeli Jews do no better than Whites in typical Western countries. Note, these figures exclude most Haredi Jews who both do rather poor on exams (see the Taub Center's reports) and who are around 80% Ashk. Thus, the testing samples tend to be less Ashk than the general population, but the excluded Ashk are substantially less proficient than average.)

Thus, as Vox notes, if one argues that Ashk Israeli come in at around 115, one has to maintain that non-Ashk Jews come in around 85. Yet, this latter conjecture is inconsistent with the variance among Jews (e.g., Figure 2, 2017 paper) and, more notably, the national scores at the 98th percentile (e.g., Figure 4, 2017 paper), a point which can be shown quantitatively. The relatively high standard deviation among Israeli Jews (about 93 versus the American White 83) does suggest subgroup differences, though.

Of course, one could make ad hoc accounts for why Ashk Jews in Israel seemingly do worse that Ashk Jews in the U.S. and ad hoc accounts for why the meta-analytic American Jewish IQ is closer to 5 IQ points above the White mean than 15. But, at this point, we are just adding epicycles.

I should note that IQ and achievement tests in Israel indicate a 0.5 to 1.0 standard deviation gap between Ashkenazi/European origin Jews and Oriental & North African origin ones. (Migrant generation, test, and sample depending.) Richard has a somewhat dated summary. Of course, I would advise checking the original studies and taking his summary statistic with a grain of salt -- as should be done with everyone.

David, H., & Lynn, R. (2007). Intelligence Differences between European and Oriental Jews in Israel. Journal of Biosocial Science, 39(3), 465-473.

My working estimate is a Ashk ~ 12 point advantage overall non-Ashk Jew in Israel. There is further differentiation between Oriental, North African, and Ethiopian Jews, of course. I base this on what Richard reported and a number of studies missed, but mean it as only a crude estimate.

If the mean Jewish Israeli IQ is about 100 normed on a typical White sample, the mean Ashk Israeli IQ would seem to be about 106.

For the record, John Fuerst is a serious scholar in the field of human intelligence. He knows as much about this stuff as anyone else, and certainly more than the long-dead scholars who cherry-picked test results from first-graders more than sixty years ago.