Admixture in the Americas: European intelligence


John Fuerst and Emil Kirkegaard have been looking at some interesting data sets, and coming to interesting and succinct conclusion, with all their workings openly available for further testing.

John Fuerst and Emil Kirkegaard. Admixture in the Americas: Regional and National Differences. MANKIND QUARTERLY 2016 56:3 256

There are also 6 critical comment for readers to look at.

We conducted novel analyses regarding the association between continental racial ancestry, cognitive ability and socioeconomic outcomes across 6 datasets: states of Mexico, States of the United States, states of Brazil, departments of Colombia, sovereign nations and all units together. We find that European ancestry is consistently and usually strongly positively correlated with cognitive ability and socioeconomic outcomes (mean r for cognitive ability = .708; for socioeconomic well-being = .643) (Sections 3-8). In most cases, including another ancestry component, in addition to European ancestry, did not increase predictive power (Section 9). At the national level, the association between European ancestry and outcomes was robust to controls for natural-environmental factors (Section 10). This was not always the case at the regional level (Section 18). It was found that genetic distance did not have predictive power independent of European ancestry (Section 10). Automatic modelling using best subset selection and lasso regression agreed in most cases that European ancestry was a non-redundant predictor (Section 11). Results were robust across 4 different ways of weighting the analyses (Section 12). It was found that the effect of European ancestry on socioeconomic outcomes was mostly mediated by cognitive ability (Section 13). We failed to find evidence of international colorism or culturalism (I.e., neither skin reflectance nor self-reported race/ethnicity showed incremental predictive ability once genomic ancestry had been taken into account) (Section 14). The association between European ancestry and cognitive outcomes was robust across a number of alternative measures of cognitive ability (Section 15). It was found that the general socioeconomic factor was not structurally different in the American sample as compared to the worldwide sample, thus justifying the use of that measure. Using Jensen's method of correlated vectors, it was found that the association between European ancestry and socioeconomic outcomes was stronger on more S factor loaded outcomes, r = .75 (Section 16). There was some evidence that tourist expenditure helped explain the relatively high socioeconomic performance of Caribbean states (Section 17).

This paper is long, very detailed and content rich, and important. It follows the new and noble practice of showing all its workings, so the diligent reader can test the findings, and in that same spirit of openness includes critical opinions from other scholars: research as it ought to be.

12 zero-order correlational analyses found a substantial positive relationship of European ancestry with both cognitive ability and general socioeconomic well- being. Multiple regression results generally found that European ancestry remained a non-redundant positive predictor when including natural- environmental predictors in the models. Socioeconomic (S factor) scores in the United States were the sole exception. More research is needed on the relationship between socioeconomic outcomes and racial ancestry in that country.

Our path analysis and semi-partial analyses indicated that cognitive ability scores can largely statistically explain the association between ancestry and socioeconomic outcomes.

The association between racial ancestry and outcomes could be mediated by genetic, cultural or other factors (Rindermann, 2015). As it has been demonstrated that indices of genetic ancestry track an array of inter- generationally transmitted cultural traits (Spolaore & Wacziarg, 2015), the results are consistent with a cultural mediation model. While the association between racial ancestry and outcomes is also consistent with an evolutionary genetic model, to obtain decisive evidence in support of such a model, one would need to identify specific alleles that vary between ancestral groups which are directly (e.g., Piffer, 2015b) or (plausibly) indirectly (e.g., Fedderke et al., 2014) associated with cognitive and/or socioeconomic outcomes at the individual level (Rindermann, 2015).

Based on a review of dozens of studies, Fuerst and Kirkegaard (2015) found that racial ancestry was associated with inter-individual socioeconomic outcome differences within admixed populations (e.g., Black Trinidadian and Toboggans) throughout the Americas (e.g., in Brazil, Chile, Colombia, Mexico, Peru, Puerto Rico, Trinidad and Tobago and the United States). Across studies, African and Amerindian ancestry was negatively and European ancestry was positively associated with socioeconomic outcomes. It is an open question, however, as to whether, on this same level of analysis, cognitive ability is robustly associated with racial ancestry and as to whether cognitive ability mediates the biogeographic ancestry-socioeconomic outcome association. There are, at present, a number of datasets which allow for the testing of these hypothesis, such as the US based Pediatric Imaging, Neurocognition and Genetics (PING) survey and The National Longitudinal Study of Adolescent to Adult Health (Add Health) survey.

As for limitations, we wish to emphasize that our national level cognitive measures were suboptimal. Our intra-national level indexes of ancestry were often likewise. Also, measurement error can give problems with multiple regression type approaches resulting in false positives (Westfall & Yarkoni, under review), and it is unknown how measurement error and the SAC measure and control methods interact. We suspect that better measures will not substantively alter the results, as they generally were robust across different analyses and different measures. Nonetheless, replicating the analyses using better and more fine- grained measures would be worthwhile.

The conclusion the authors come to is that to understand the intelligence and social achievements of people in the United States of America, Mexico, Brazil and Colombia you need to know only one thing: how much European ancestry they have. This is pretty much a consistent finding in their samples, but they look through many other possible explanations, such as the contributions of other genetic groups, the special contribution of tourism to economies, and the depredations of other factors like parasite load, all covered in detail in their paper.

Here are the pictures for each of the states or provinces, and then the composite picture.

European ancestry and Mexican states

European ancestry and US states

European ancestry and Brazilian state

European ancestry and Colombian departments

European ancestry and nations

Above is the picture for sovereign nations.


European ancestry, states and nations combined


So, that’s the Americas sorted out. With the partial exception of US states, to the extent that they are European, they are bright and successful.

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