The evidence exists, however, the causes are more obvious: 1) **the size of the underclasses. **and **2) neotonic(pedomorphic) evolution – meaning the retention of childhood features, **and 3)** transfer of female verbal acuity to males because of pedomorphic evolution.**
Cold Climates, Agrarianism, Manorialism, and the raw Capital Costs of Tools (metals) needed to survive in those conditions, in addition to the aggressive hanging of the underclasses for more than a thousand years, allowed both upward redistribution of calories and reproduction, and the downward population of labor by the middle genetic classes.
So by the time of the industrial revolution (if not the literacy revolution) europe (and west asia) had vast stores of underutilized human capital. However, both had to break free of the church and the bureaucracy which had made the vast majority of capital “dead” (static) and in support of rent seeking (church bureaucracy and chinese imperial bureaucracy).
For the rest of the world, they have been unsuccessful at one or both of two factors: either (a) decimating the underclasses, and (b) developing deflationary grammars (methods) in the sequence math, logics, reason, empirical law (tort), and science.
West europeans and east asians and ashkenazi were able to limit the size of their underclasses and to force upward redistribution of reproduction. East asians have the highest Neoteny, West Europeans, and then Ashkenazi. And less visible testosterone levels to equal more visible morphology(features).
This is the primary difference between the races and subraces: Degree of neoteny, and distribution of male and female traits (brain structures) between the genders. Strangely enough, in the Ashkenazi they have nearly reversed it. Which is why they have such exceptional verbal (if not spatial) skills.
So that’s the state of the science as I understand it.
in other words, the greatest material differences are driven by the size of the underclasses, and therefore the median distribution in the gene pool, and therefore the language, norms, traditions, and institutions necessary or the persistence of such a gene pool with such a distribution.
All of this is very simple. The marxist-postmodernist-feminist attempt at the second dark age – this time of pseudoscience – just made us lose a century and a half to their deceptions.