Spent too long on other stuff today. This is another copy-pasta from a VP comment.
Observation from another side of the internet: high-IQ European Jews do not have the same phrenology markers as other high-IQ Europeans (who tend to express remnant traits of neanderthals, et al.). In fact, they are often indistinguishable from Ashkenazim of average intelligence (~112 IQ). This suggests their eugenic striation was much more recent, and involved selection of preferred traits from various European races (this latter is suggested because a German Jew looks more like a French Jew than a white German).
[Ed: Credit for the observation in the first two sentences goes to polymath. Implications drawn in the latter sentence is mine.
Personally, I’ve theorized that Ashkenazi eugenics is due to their habit of getting the dumber and poorer Jews Holocausted due to the actions of their richer, smarter elites (who escape and reproduce the cycle in another country).
[Ed: More on this here.]