American university students may have the highest IQs because our system is the most meritocratic, and we have long used the (formerly) IQ proxy SAT for college admissions. The average PhD has an IQ of 130, IIRC, but that doesn't stop them from being Democrats. And, the vaunted Germans are socialist lemmings. I always heard that the average white American IQ was 100 by definition (i.e. the tests were developed here and normed to our population around the 1st World War). Average Jewish IQ was supposed to be around 108, and the average for Japanese and Chinese around 110 (but undestand for Japan and China it would have been a relatively small subset of the population who were tested, not a true cross section - or perhaps that was for Japanese and Chinese in the US, which would make sense).
I have read that Askenazi Jews are an unusual group when it comes to this topic. You quoted the 108 number for Americans who are Jews, but they are not all from the Ashkenazi.
Apparently 1000 years of ghettoization, a fairly signficant amount of inbreeding and being forced into certain jobs may have been a strange experiment in genetic engineering.
The existence of Tay-sachs in this population is also a consequence. The theory goes that bankers and jewellers and the other professions to which Jews were limited during the middle ages required high IQs to be done properly. As a result, natural selection favoured those who had higher IQs. However, the brain requires a very large amount of a special kind of fat (actually cholesterol). If you get one gene taht allows for the excess fat to be present, you are smart. If you get 2, you get Tay-Sachs.
It is just a theory, but an interesting one. I am looking for where I found it. I think it might have been a blurb in the Economist.
What do you think?