Answering this question as a post because it comes up a lot, and I don’t feel like writing anything else today.
How come Jews have slanted heads in the front and supposedly less frontal lobe space and are verbally excellent. As opposed to this guy, Andrew Jackson, with mucho frontal lobes?
Well firstly, we cannot assume Andrew Jackson has mucho frontal lobes unless we have an MRI for him or something, because phrenology only does correlations. So it is probably the case, but what we really know with a useful degree certainty is that Andrew Jackson comes from a race of people with high verbal IQs via frontal lobe, because skull shapes are a very good racial indicator.
NB: it presently appears that the correlation between the skull shapes of edenic races and the cognitive traits of those races becomes greater as the skull shape becomes more pronounced. For instance, a melonhead like BF Skinner’s seems to have quite high predictive validity:
But a bump in the parietal region that is only slightly above average for a person’s racial mean rarely has any predictive significance. So it is not like the correlation between IQ and height, where every little bit of height bumps up the IQ estimate a little bit. We are essentially limited to prediction in extreme cases.
Examples of extreme melon backs: BF Skinner, Hans Bethe, Goethe. Extreme melon fronts: Caesar, Cauchy, Rachmanimoff. Extreme thal fronts: Lord Kelvin, Ivan Turgenev, Jack Palance, and several American Indians. Extreme thal backs are harder to come by, but Ettore Majorana is a good one and also this random Basque guy:
Secondly, I don’t know that it’s necessarily true that Jews have the slanty heads in front. It does seem to be true for Jews defined broadly, but we have to account for 1) the existence of Nazi propaganda and 2) the more brachycephalic Western Ashkenazi (I believe they are “alpinized” Jews in Coon’s Races, though I’ve only scanned it).
Thirdly, we have the fact that edenic phrenology does not seem to work on Ashkenazi whatsoever. To expand on the latter point, it seems that because the Ashkenazi eugenics project was very recent in anthropological timescales, their IQs are not related to their expressions of archaic phenotypes like melon, thal, etc. This seems to be the case for both the face and the braincase, as extraordinarily bright Jews like von Neumann and Sidis look like ordinary Ashkenazi. It seems that Jews may therefore be considered a separate archetype with similar predictive power as the edenic races: that is, the more neanderthal a person looks, the more likely they will have a neanderthal-like brain, and the more Jewish a person looks the more likely they will have a Jew-like brain.
(The same might be said of the Amish in a few hundred years, if they keep up the good work.)
Now, I have to account for the fact that what I write about is a bit broader than the edenic stuff. For instance, a frontal lobe is a frontal lobe regardless of where it came from. So! Where is this extra juice coming from? For this we have to dip into parieto-frontal integration theory, which is a real scienc-ey thing and not just some weirdo running his mouth on the internet.
It is readily observed that extraordinary Jewish intelligence is both verbal and mathematical in nature. My running theory is that it is essentially impossible to get above the 130 IQ mark for intelligence with just a high-functioning frontal lobe. So I believe that all this, taken together, indicates that Ashkenazi will tend to have parietal lobes that are much more developed than we would otherwise expect.