I would be very surprised if high intelligence was anything other than the extreme edge of a normal distribution of the human population. For it to be anything other than this it would require people of high intelligence to be a sub-population that did not breed with the rest of humanity.
'would require people of high intelligence to be a sub-population that did not breed with the rest of humanity' - which is increasingly what is happening with people of high ability & potential income of both sexes attending the same universities and mating. This polarization has been documented.
It's not even that mating like that is increasingly happening--- it's been that way in nobility for a long time.
What is the True Rate of Social Mobility in Sweden? A Surname Analysis, 1700-2012 http://www.econ.ucdavis.edu/faculty/gclark/papers/Sweden%202...
Skimmed through that one a bit.. I think he misses that having a patronym surname (ending with son) is very much out of fashion in Sweden today (and has been for quite some time), so people change it. The people most likely to change it are probably found in the more "elite" professions the author lists. If you're a blue-collar it may feel a bit presumptuous to change your surname, you will be ridiculed by your coworkers. OTOH if you're an attorney, it's almost mandated, "no one" will trust you if you have a patronym surname.
Good point, but I believe he addresses that:
> One thing we have to be wary of in this calculation of persistence is surname changing. If people going to the university born with the surname Anderson were changing this to Wigonius, then there would appear more persistence than there really was. The biographical sources for some of the student nations at Lund and Uppsala, Blekingska, Göteborgs, Skånska, Smålands, and Vermlands at Lund, and Östgöta at Uppsala, allow us to estimate the fraction of Latinized surnames which were newly adopted in each generation at the universities, since it gives fathers’ and mothers’ surnames for most students also. Figure 19 shows what fraction of students in each generation inherited rather than adopted a Latinized surname.18 For the earlier generations, 1730-1819, 96% of students acquired the name by inheritance from their father. However, 1820-1909 that proportion fell to 88%, even though by design these are all surnames that first existed before 1730.19 This will bias upwards my estimate of b, but can be corrected for by calculating for each period a b based just on the relative representation of the surname among the inheritors in that period.
Greg Clark’s A farewell to Alms is a very approachable overview to his research [1].