Monday, February 24, 2020

Between Europe and America



Iceland had pre-Columbian contacts with North America. Did they lead to intermarriage? (Wikicommons)



Did the Norse have sustained contacts with the indigenous peoples of the Americas, including intermarriage? Or was Vinland a fleeting encounter?

Steve Sailer touched on this question in a recent column, citing an Icelandic study. Although Iceland’s gene pool is overwhelmingly from Scandinavia and the British Isles, there are also traces of a lineage normally found among the indigenous peoples of northeast Asia and the Americas. Preliminary genealogical analyses have shown that this lineage was present in Iceland at least 300 years ago. 

This raised the intriguing possibility that the Icelandic C1 lineage could be traced to Viking voyages to the Americas that commenced in the 10th century. In an attempt to shed further light on the entry date of the C1 lineage into the Icelandic mtDNA pool and its geographical origin, we used the deCODE Genetics genealogical database to identify additional matrilineal ancestors that carry the C1 lineage and then sequenced the complete mtDNA genome of 11 contemporary C1 carriers from four different matrilines. Our results indicate a latest possible arrival date in Iceland of just prior to 1700 and a likely arrival date centuries earlier. Most surprisingly, we demonstrate that the Icelandic C1 lineage does not belong to any of the four known Native American (C1b, C1c, and C1d) or Asian (C1a) subclades of haplogroup C1. Rather, it is presently the only known member of a new subclade, C1e. (Ebenesersdóttir et al. 2011)

I doubt the hypothesis of Amerindian admixture. As the authors note, the C1e subclade has not been found in any indigenous population of the Americas. Perhaps this is because those populations have not been studied as thoroughly as the Icelandic one. Perhaps it is present among Amerindians, but at a frequency too low to be detected by studies done to date.

But why, then, do we see no other Amerindian subclades in Icelanders? That population has been studied so exhaustively that even low frequencies of other subclades should have been detected by now. This point is made by Der Sarkissian et al. (2014):

Among other hypotheses including that of a European origin, an American origin was favoured on the basis that most of the hg C1 diversity is found on the American continent, despite the fact that no sequence belonging to hg C1e could be detected in the Americas (or anywhere else). This lack of match was explained by under-sampling of the American mtDNA genome diversity [10]. In any case, if admixture between Native Americans and Vikings did occur, it must have been limited, as no other American-specific lineage (e.g. hg A2, B2, D1, C1b, C1c, C1d) was detected in Iceland.

The authors of the same study point out that a sister subclade, C1f, has been found in human remains from Mesolithic northeast Europe. Moreover, it is not excluded that these two sister subclades, C1e and C1f, still exist in northeast Europe. The Icelandic population has been studied much more than almost any other population, so C1e might still exist somewhere in northeast Europe but hasn't been found because of its low frequency. The authors conclude:

... we suggest that the Icelandic-specific C1e sub-clade could have had a recent origin in northern Europe rather than an American origin. This hypothesis is relevant with regard to the origins of the Icelandic population, as Iceland was discovered and first settled by Scandinavian Vikings around 1,130 years ago. Vikings raids extended as far from their homeland in Scandinavia as France, Spain and Sicily, but their main expansion range comprised western Russia, the Baltic region, Scandinavia, and the British Isles.

In fact, we know that some of Iceland's settlers had trading contacts with Russia and may have had slaves of Slavic origin:

No name given in Landnámabók resembles any Slavic form. But the settlers who came from Sweden and Gotland (e.g. S. 209) must have had various contacts with the Slavs. This would be the case also with some Norwegians who like Skinna-Bjöm 'used to go trading to Novgorod' before he went to Iceland. His son Miðjarðar-Skeggi 'went to plunder in the Baltic' (S. 174 and H. 140). Such people were very likely to have aboard their ships Slavic slaves and/or companions recruited from among southern Baltic pirates or inhabitants of the multiethnic emporia like Wolin/Jómsborg or Truso. (Urbanczyk 2002, p. 160)

A Slavic presence in Iceland is further suggested by the existence of "sunken huts"—rectangular-like depressions in the ground with vertical walls, stone ovens placed in one of the corners, and roof constructions supported by corner posts. To date, the remains of eighteen such huts have been discovered in Iceland, and they seem to date to the settlement period. They are also typically Slavic:

Considering the houses they built there is little alternative to the conclusion that they were Slavs or, at least, people who grew up among the Slavs which made them 'Slavs' culturally. Such houses, distinctively different from the Germanic sunken huts are known in thousands from all the lands settled by early Slavs in Eastern, Southern and Central Europe. (Urbanczyk 2002, p. 163)

It should be pointed out that the Norse were major players in the early medieval slave trade, particularly in supplying North African and Middle Eastern clients with fair-skinned women. One of the largest slave markets was at Hederby, on what is now the Danish-German border. It was largely to cash in on the demand for slaves that the Norse began launching their infamous raids across Europe (Holm 1986; Raffield 2019; Skirda 2010, 143-146). Regular visits by Muslim merchants likely explain the influx of Middle Eastern silver coins into Scandinavia during the ninth and tenth centuries (Raffield 2019). 

Such visits may also explain the presence of low levels of North African ancestry in the Icelandic gene pool. Ásmundsdóttir (2017) argues that this North African ancestry entered the Icelandic gene pool by way of the initial Scandinavian settlers. It may thus have its origins in merchants from Muslim Spain and North Africa who regularly came to trading centers like Hederby.


References

Ásmundsdóttir R.D. (2017). The African L3e5a haplogroup in the Icelandic population.
Skemman repository of dissertations
https://skemman.is/handle/1946/27644

Der Sarkissian, C., P. Brotherton, O. Balanovsky, J.E. Templeton, B. Llamas, J. Soubrier, V. Moiseyev, V. Khartanovich, A. Cooper, W. Haak, and Genographic Consortium (2014). Mitochondrial genome sequencing in Mesolithic North East Europe Unearths a new sub-clade within the broadly distributed human haplogroup C1. PloS one 9(2), e87612. 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3913659/ 

Ebenesersdóttir, S.S., Á. Sigurðsson, F. Sánchez-Quinto, C. Lalueza-Fox, K. Stefánsson, and A. Helgason, (2011). A new subclade of mtDNA haplogroup C1 found in icelanders: Evidence of pre-columbian contact? American Journal of Physical Anthropology 144: 92-99.
https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.21419

Holm, P. (1986). The Slave trade of Dublin, Ninth to Twelfth Centuries. Peritia 5: 317-45.

Raffield, B. (2019). The Slave Markets of the Viking World: Comparative Perspectives on an 'Invisible Archaeology'. Slavery & Abolition 40(4)

Sailer, S. (2020). Are Any Living Humans Descended from Pre-1492 Trans-Atlantic Contacts? The Unz Review, February 20
https://www.unz.com/isteve/are-any-living-humans-descended-from-pre-1492-trans-atlantic-contacts/#new_comments

Skirda, A. (2010). La traite des Slaves. L'esclavage des Blancs du VIIIe au XVIIIe siècle. Paris: Les Éditions de Paris Max Chaleil.

Urbanczyk, P. (2002). Ethnic aspects of the settlement of Iceland. Collegium medievale: interdisciplinary journal of medieval research 15:155-166
http://www.mgh-bibliothek.de/dokumente/b/b071118.pdf

Monday, February 17, 2020

A Pandora's box?



Chinese lung tissue seems to be receptive to coronaviruses, perhaps because frequent mild infections stimulate the immune system to protect against more serious pulmonary infections, like pneumonia and tuberculosis. This may be why China escaped the ravages of the Spanish flu in 1918. Have modern measures for public health opened a Pandora's box in China? (Wikipedia – CDC)



Are Chinese people more vulnerable than others to the Wuhan coronavirus? The question is raised by Zhao et al. (2020), who examined lung tissues from several donors and studied a receptor that acts as the point of entry for some coronaviruses, including the ones responsible for the SARS outbreak of 2002-2003 and the ongoing outbreak in Wuhan, China. They found that the receptor was concentrated in cells that promote viral reproduction and transmission. They also found that the number of these cells in lung tissue varied with ethnic origin:

A comparison between eight individual samples demonstrated that the Asian male one has an extremely large number of ACE2-expressing cells in the lung. We also noticed that the only Asian donor (male) has a much higher ACE2-expressing cell ratio than white and African American donors (2.50% vs. 0.47% of all cells). This might explain the observation that the new Coronavirus pandemic and previous SARS-Cov pandemic are concentrated in the Asian area.

This study is a preprint and has not yet been peer-reviewed, a fact highlighted in a notice placed above the online paper:

bioRxiv is receiving many new papers on coronavirus 2019-nCoV. A reminder: these are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information.

I often consult bioRxiv, and this is the first time I've seen such a notice. It's not as if this study has been widely publicized in the mainstream media.

A peer reviewer would make the same criticism that the authors themselves make: the sample size is small. In fact, there was only one Asian in the entire sample. Nevertheless, sampling error cannot easily explain the five-fold difference between the Asian donor and the non-Asian ones. Moreover, this finding is consistent with those of previous studies. Cheng et al. (2007) looked at other receptors for viral infections and found differences between Chinese and other human populations. In the specific case of pulmonary diseases, Seitz et al. (2012) studied the prevalence of bronchiectasis in the United States and found that Asian Americans had a prevalence 2.5 to 3.9 times higher than those of Euro Americans and African Americans. Kwak et al. (2010) similarly found a high prevalence of bronchiectasis in Korean adults.

These ethnic differences should be no surprise. Many pathogens can infect some populations more easily than others. This was shown by a study of the TLR2 polymorphism, which influences resistance to such infections as leprosy, tuberculosis, staphylococcal infections, and sepsis:

Interestingly, recent data have pointed out that TLR2 polymorphisms are associated with disseminated tuberculosis or exert specific effects on susceptibility to certain mycobacterial strains, such as the Beijing strains of Mycobacterium tuberculosis. The Beijing strains have a clear geographical distribution, raising the possibility that human TLR2 has coevolved in various populations depending on the type of infectious pressure in a particular region, similarly to what has been reported for polymorphisms in other innate immune genes such as TLR4 or Mal/TIRAP. (Iona et al. 2012)

The argument here is that an infectious disease will favor the survival and reproduction of those people who are more resistant to it. So, over succeeding generations, the average person will become naturally more resistant. The degree of resistance will vary from one population to another because the incidence of infectious pathogens typically varies from one population to another.

In this case, the average Chinese person seems to be naturally less resistant to coronaviruses. That is a bit surprising. The Chinese have cohabited with various forms of livestock for a long time, longer than most humans, and should have become more resistant to viral infections that jump the species barrier, like the current coronavirus in Wuhan. Yet, here, the reverse is true.

Perhaps we're looking at this coevolution the wrong way. Perhaps coronaviruses usually do more good than harm. Perhaps, over time, there has been selection to make the average Chinese person less resistant to them. This possibility has been explored in a recent paper by Shekhar et al. (2017). Certain viral infections of the respiratory tract seem to help their hosts by boosting resistance to bacterial infections:

Little is known about the interaction of the host with commensal viruses and fungi that inhabit the respiratory system. Latent infection with herpesviruses can lead to opportunistic infections in immunocompromised individuals. Recent findings, however, highlight a new role for these viruses in increasing host resistance to bacterial infections. Infection with herpesviruses in mice results in chronic production of large quantities of IFN-γ and activation of macrophages that confer protection from subsequent infection with Listeria monocytogenes and Yersinia pestis. (Shekhar et al. 2017)

So you periodically come down with a mild flu, and you can better resist more serious pulmonary infections, like pneumonia and tuberculosis. Of course, now and again, the flu might be deadly, like the one in 1918. Interestingly, China was largely unaffected by the Spanish flu pandemic: "in 1918, China was spared from the worst ravages of the pandemic, due to the apparent greater resistance to the virus among the Chinese population compared to other regions of the world" (Wikipedia 2020).

Since then, public hygiene measures have steadily reduced chronic exposure to mild pulmonary infections in the Chinese population. If the Spanish flu struck China today, would the Chinese people be just as unaffected? Is this why the Wuhan outbreak has been so severe?


Conclusion

The Chinese population has developed a commensal relationship with coronaviruses, which are usually mild and seem to prepare the immune system for serious pulmonary infections. Through a process of coevolution, the Chinese have become five times more susceptible to coronaviruses than other human populations. 

Far from being an enemy, these viruses may actually be a friend that plays a valuable immunological role. By creating a cleaner social environment, the Chinese authorities may have unwittingly opened a Pandora's box. 

As for non-Chinese people, it doesn't follow that they will be immune to the new coronavirus, only that they will be less vulnerable.

On a final note, the economic disruption due to the Wuhan outbreak will lead to a contraction in Chinese production, and this contraction will exacerbate the ongoing problem of China's shrinking workforce. There are going to be fewer and more expensive consumer goods on the global market. Ironically, all of this is happening as we enter the 2020s—a decade already predicted to be a time of crisis. 


References

Cheng, P-L, H-L. Eng, M-H. Chou, H-L. You, T-M. Lin, (2007). Genetic polymorphisms of viral infection-associated Toll-like receptors in Chinese population. Translational Research 150(5): 311-318
https://www.sciencedirect.com/science/article/pii/S1931524407000953 

Ioana, M., B. Ferwerda, T. S. Plantinga, M. Stappers, M. Oosting, M. McCall, A. Cimpoeru, F. Burada, N. Panduru, R. Sauerwein, O. Doumbo, J. W. M. van der Meer, R. van Crevel, L. A. B. Joosten, and M. G. Netea. (2012). Different Patterns of Toll-Like Receptor 2 Polymorphisms in Populations of Various Ethnic and Geographic Origins. Infection and Immunity 80(5): 1917-1922
https://iai.asm.org/content/80/5/1917 

Kwak, H.J., J.Y. Moon, Y.W. Choi, T.H. Kim, J.W. Sohn, H.J. Yoon, D.H. Shin, S.S. Park, and S.H. Kim. (2010). High prevalence of bronchiectasis in adults: analysis of CT findings in a health screening program. Tohoku Journal of Experimental Medicine 222: 237-242.
https://pdfs.semanticscholar.org/dd5d/c5d64f82c84277b74024af0671c8ec070fa6.pdf

Seitz, A.E., K.N. Olivier, J. Adjemian, S.M. Holland, and D.R. Prevots. (2012). Trends in bronchiectasis among medicare beneficiaries in the United States, 2000 to 2007. Chest 142(2):432-439.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3425339/

Shekhar, S., K. Schenck, and F. C. Petersen (2017). Exploring Host-Commensal Interactions in the Respiratory Tract. Frontiers in Immunology 8: 1971
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5776090/  

Wikipedia. (2020). Spanish flu
https://en.wikipedia.org/wiki/Spanish_flu 

Zhao, Y., Z. Zhao, Y. Wang, Y. Zhou, Y. Ma, and W. Zuo. (2020). Single-cell RNA expression profiling of ACE2, the putative receptor of Wuhan 2019-nCov. bioRxiv January 26
https://www.biorxiv.org/content/10.1101/2020.01.26.919985v1.full


Wednesday, January 22, 2020

The costs of outbreeding: a few more points



Although the house mouse (Mus musculus) is a single species, fertility is reduced in crosses between geographic populations (Wikipedia - Bolid74)



It's widely believed that mating between two species never produces fertile offspring. Untrue. Interspecific mating sometimes produces fertile offspring, and the genomes of closely related species often show gene flow from one to the other. It would be more accurate to say that such crossings are usually compromised in one way or another—incompatibilities arise during development, which lead to miscarriage, sterile offspring, or less viable offspring. 

There is a similar misunderstanding about mating within a species. It isn't true that mating within a species is uniformly possible. Even below the species level, genetic incompatibilities can arise between different geographic populations. Keep in mind the arbitrariness of all these terms: “geographic population,” “race,” “subspecies,” and “species.” These are points on a continuum of increasing reproductive isolation and genetic incompatibility. 

Various problems have been observed in crossings between geographic populations of the same species (Presgraves 2010; Turner et al. 2011). In the case of crossings between two subspecies of the house mouse (M. m. domesticus and M. m. musculus), the problems have no single cause. There is not only reduced fertility but also reduced immune function, as shown by higher loads of intestinal parasites in hybrids. Even the reduction in fertility has multiple causes: "The type and severity of fertility defects observed depends on the geographic origin of the strains and also varies among individuals within regions. This variability suggests that multiple genetic incompatibilities contribute to hybrid male sterility" (Turner et al. 2011). Multiple loci seem to be responsible, and incompatibilities that cause sterility likely act in combination with each other and with other incompatibilities (Turner et al. 2011).

In general, as genetic distance increases, so does the risk of faulty interactions between different gene loci:

The Dobzhansky-Muller model proposes that populations diverging independently in allopatry will accumulate differences through drift or selection, but will maintain coadaptation between divergent loci within each single population. If secondary contact and hybridization occurs between these populations, these divergent loci from the previously allopatric populations may interact deleteriously in hybrids leading to lowered hybrid fitness (Leppälä and Savolainen 2011)


Icelandic and Danish studies on outbreeding

The above model is consistent with two recent studies on humans, one in Iceland and the other in Denmark. The Icelandic study used a database of couples born between 1800 and 1965. In the authors' own words, "the advantage of using the Icelandic data set lies in this population being small and one of the most socioeconomically and culturally homogeneous societies in the world, with little variation in family size, use of contraceptives, and marriage practices" (Helgason et al. 2008). The authors found that fertility rose and then fell with increasing genetic distance between husband and wife. Specifically, the relationship was:

[...] an n-shaped curve from the relatively low reproductive success of couples related at the level of second cousins or closer, to the maximum for couples related at the level of third and fourth cousins, after which there is a steady decrease in reproductive success with diminishing kinship between spouses. A similar picture emerges when the number of grandchildren per couple is examined (Helgason et al. 2008)

The Icelandic study was criticized in a tweet by Jayman:

Doubt it. The Icelandic study is likely confounded in various ways so I don't think genetic relatedness is the thing directly affecting fertility.

He was retweeted by hbdchick, but neither of them identified the "various" confounds. Nor did I find this criticism in the 140 papers that cited the study on Google Scholar. So we're not in the realm of common knowledge.

The original paper did identify a possible confound. From 1800 to 1965, there was a decrease in mean fertility and an increase in marriages with more distantly related individuals. The relationship between fertility and kinship may thus be an historical confound:

These results are based on couples born during a period of almost 200 years, in the course of which there was a marked decline both in the mean fertility and in kinship between couples. (Helgason et al. 2008)

To eliminate the confound, the authors broke the data down by 25-year intervals:

Nonetheless, the same general relationship between kinship and reproductive outcome was observed within each 25-year subinterval (fig. S2). We evaluated the correlation between the standardized variables of kinship and reproductive outcome for all couples and for each time interval separately (Table 2), adjusting for the impact of geographical differences in the kinship and fertility of couples within Iceland (10). Each test revealed as significant association with kinship, with correlation coefficients of 0.063 (P = 1.5 × 10-129) for the number of children, 0.045 (P = 3.6 × 10-66) for the number of children who reproduced, and 0.042 (P = 7.6 × 10 -58) for the number of grandchildren. (Helgason et al. 2008)

There might be other confounds. That's why the Danish study is important. It went through a number of socioeconomic factors: "education, family income, urbanicity, mother's age at first birth, and six variables representing proximity to kin [maternal radius, i.e., distance between mother's and child's birthplace; paternal radius; and presence of each grandparent in the child's birth parish or neighboring parish" (Laboriau and Amorim 2008). Controlling for those factors did not change the findings.


Davenport's study on outbreeding in Jamaica

Jayman also criticized Davenport's study, apparently in reference to the finding that between 5 and 30% of the "brown" children did worse than predicted.

As for mixed race children, you have to keep in mind that people don't enter those relationships randomly - i.e., also confounded

Jayman is arguing that the parents of the brown children were atypical, apparently in the sense of being below-average. In its early days, Jamaica did have many poor whites, but most of them left because of competition from slave labor. European ancestry entered the Jamaican population largely from landowners and businessmen, particularly people of Scottish descent:

Jamaica has more people using the Campbell surnames than the population of Scotland itself, and it also has the highest percentage of Scottish surnames outside of Scotland. Scottish surnames account to about 60% of the surnames in the Jamaican phone books. The first Jamaican inhabitants from Scotland were exiled "rebels". Later, they would be followed by ambitious businessmen who spent time between their great country estates in Scotland and the island. As a result, many of the slave owning plantations on the island were owned by Scottish men, and thus a large number of mixed-race Jamaicans can claim Scottish ancestry. (Wikipedia 2020).

Today, "brown" Jamaicans are generally middle class, and they were even more so during the time of Davenport's study. It is indeed strange to intimate that his biracial subjects were the offspring of below-average whites and blacks.


Conclusion

Davenport's study probably corresponds to the highest degree of outbreeding possible. Even in that case, adverse mental effects were observable only in a minority of offspring. The most widespread effect is probably lower fertility and perhaps a higher risk of testicular cancer. Joffe (2009) suggests that an increase in outbreeding might explain a century-long decrease in semen quality and a corresponding increase in testicular cancer:

One implication of the proposed pathogenesis is that as D&D [duplications and deletions of genetic material during meiosis] accumulate, mating between individuals who are genetically unalike would be associated with lower reproductive success as pairing at the start of meiosis would be more likely to be impaired. On the face of it, this contradicts the earlier observation that hybrid vigour would tend to increase fertility in unrelated individuals. Yet these two ideas may be compatible: both extremes—genetic similarity (inbreeding) and genetic distance (D&D accumulation)—could decrease fertility, so that an intermediate degree of relatedness would be associated with the highest degree of fertility. This could explain the evidence from Iceland that the greatest reproductive success, measured as the number of grandchildren, was observed in couples who were third or fourth cousins (Helgason et al., 2008). Comparable findings have been reported from elsewhere, for example Denmark (Labouriau and Amorim, 2008).

I realize this may be a sensitive subject. If you feel offended, please read something else.


References

Davenport, C.B. and M. Steggerda. (1928). Race Crossing in Jamaica. Washington: Carnegie Institution, Publication no. 395.
http://www.velesova-sloboda.info/archiv/pdf/davenport-race-crossing-in-jamaica.pdf  

Helgason, A., S. Pálsson, D.F. Guðbjartsson, þ. Kristjánsson, K. Stefánsson. (2008). An association between the kinship and fertility of human couples. Science 319(5864): 813-816.
http://facelab.org/debruine/Teaching/EvPsych/files/Helgason_2008.pdf   

Joffe, M. (2009). What has happened to human fertility? Human Reproduction 25(2): 295-307.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1003.7270&rep=rep1&type=pdf 

Labouriau, R., and A. Amorim. (2008). Comment on "An Association Between the Kinship and Fertility of Human Couples." Science 322(5908): 1634
http://science.sciencemag.org/content/322/5908/1634.2.full   

Leppälä, J. and O. Savolainen. (2011). Nuclear-cytoplasmic interactions reduce male fertility in hybrids of Arabidopsis lyrata subspecies. Evolution 65(10): 2959-2972
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1558-5646.2011.01361.x

Presgraves, D.C. (2010). The molecular evolutionary basis of species formation. Nature Reviews Genetics 11:175-180.
https://www.nature.com/articles/nrg2718  

Turner, L.M., D.J. Schwahn, and B. Harr. (2011). Reduced male fertility is common but highly variable in form and severity in a natural house mouse hybrid zone. Evolution 66(2): 443-458.
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1558-5646.2011.01445.x  

Wikipedia (2020). Jamaica
https://en.wikipedia.org/wiki/Jamaica

Tuesday, January 14, 2020

The costs of outbreeding: what do we know?



Charles Davenport, circa 1929 (Wikicommons)



To produce healthy children, you should marry a third or fourth cousin. Farther out, the genetic costs of outbreeding begin to outweigh those of inbreeding. That was what a cohort study found in examining Icelanders born between 1800 and 1964. Fertility was lower if the woman's husband was either closer in or farther out (Helgason et al. 2008).

That finding is supported by a Danish study. Using data on Danes born in 1954, the authors measured the distance between the wife's home parish and the husband's home parish. Fertility peaked at a distance of around 75 km. The relationship between fertility and marital radius was not explained by education, family income, urbanicity, or mother's age at first birth. The authors concluded that their findings were consistent with those of the Icelandic study, the cause being the same: fertility rises with decreasing relatedness up to a peak and then starts to fall. Inbreeding depression gives way to outbreeding depression (Labouriau and Amorim 2008).

How far can you marry out before the costs of outbreeding become unacceptable? One problem lies with that word. What may be perfectly acceptable to one person may not be to another.

So let me review what is known and what remains to be known. You be the judge.

A half-century ago, Ernst Mayr wrote: "Hybridization between species leads almost invariably to unbalance through deleterious combinations of genes. [...] in Drosophila even the hybridization of races may lead to destruction of well-integrated gene combinations" (Mayr 1970, p. 399). He then went on to say that it is "still uncertain" whether these findings apply to our species. In fact, "all investigations of race mixtures in man have failed to produce any evidence of decreased fitness."

It would be better to say "indisputable evidence." In fact, there is evidence from two major studies of the 1920s.


Davenport’s research in Jamaica

I will begin with a study by Charles Davenport, a Harvard zoology professor. In the early years of the twentieth century, he became concerned about human heredity and the genetic consequences of outbreeding. In 1926, with his assistant Morris Steggerda, he went to Jamaica and examined 100 black, 100 white and 100 “brown” adults of equal social status, together with 1200 children between the ages of 10 and 16. They were given anthropometric, physiological, and psychological tests. The psychological results are worth quoting in full:

Disharmonies in the mental sphere are socially more significant, perhaps, than those in the physical sphere, and such disharmonies are apparently common in the adult Browns [...]. Such disharmony and confusion apparently appear in visualization and reproduction, as in putting together the parts of the manikin. The proportion of failures of the Browns is 9.6 per cent, as opposed to 3.1 per cent in Blacks and 2.1 per cent in Whites. In copying of geometric figures 5 per cent of Browns fail completely, as compared with 3 per cent of the Blacks and 0 per cent of the Whites. In the Army Alpha Test IV (opposites and similars) 41 per cent of Browns got only 3.7 or fewer correct, while only 23 per cent of Blacks did so poorly and none of the Whites. In Test V (pied sentences) 30 per cent of the Browns got fewer than 3 out of 24 questions right, while only 26 per cent of the Blacks and 13 per cent of the Whites did. In Test VII (of analogies) 45 per cent of the Browns got less than 10 per cent of the questions correct, while only 30 per cent of the Blacks and 21 per cent of the Whites did so badly. One gains the general impression that, though on the average the Browns did not do so badly, there was among them a greater number of persons than in either Blacks or Whites who were muddled and wuzzle-headed. The Blacks may have low intelligence, but they generally can use what they have in fairly effective fashion; but among the Browns there appear to be an extra 5 per cent who seem not to be able to utilize their native endowment. There are so many variables, however, and the numbers are so small, that the results merely propose an hypothesis and do not warrant a conclusion.

The question arises: are there any traits in which, on the average, the adult Browns are superior to the Whites? We might, theoretically, expect such, yet when we have tested all of the probably genetically distinct traits between Blacks and Whites, we find only one in which the mean of the adult Browns is clearly higher than that of either parental stock.

On the other hand, if we examine the means for children of 10 to 13 or 13 to 16 years there are a few in which the brown children grade higher than either the black or the white children. [...] The fact that youthful Browns sometimes score higher than youthful Blacks or Whites suggests the conclusion that brown children develop in some mental capacities precociously; and then fall behind in development.

The relative underperformance of biracial individuals looks significant, given the sample sizes. Less clear is its magnitude and, most importantly, its cause. If we exclude the hypothesis of incompatibilities during development, there are only two other explanations:

- The “brown” individuals had suffered some kind of deprivation that the black and white individuals hadn't.

- “Brown” individuals with mental problems had been oversampled.

Neither explanation seems likely. In the Jamaica of the 1920s, biracial individuals were if anything a privileged group. They dominated the middle class. Nor is it clear why those with mental problems would be oversampled. 


Mjøen’s research in Norway and Sweden

The second study was by Jon Alfred Hansen Mjøen, a Norwegian who in 1906 founded the Vinderen Biological Laboratory, a center for international research in genetics. He likewise was concerned about the possible negative effects of outbreeding and became a proponent of eugenics. In 1934, he supported a Norwegian law for forced sterilization. He died in 1939. 

With the support of his laboratory, Mjøen did fieldwork in northern Norway and Sweden, where he observed and measured about 600 Norwegians/Swedes, about 600 Sami, and more than 300 people of first-generation mixed ancestry. Most individuals in the last group were described as having "harmonious faces, general good looks, decent stature, height, and strength, as well as a good correlation between volume of lungs and body-size, and muscular strength and body-size." However, "we found more disharmonies, both physical and mental, than in the two parent races."

The disharmonies were: "Relatively large or small ears, disproportionate extremities, unusual length of body in the F1 generation, abnormal range of variation with regard to such characteristics as lung-volume and muscular strength [...], greater prevalence of diabetes [...], loss of balance, and diminished resistance to tuberculosis" (Mjøen 1931).

Mjøen argued that disharmonies are most likely to occur when a trait is determined by large numbers of genes acting together, such as when hormones act on genes for growth and development: "It is highly probable that the frequently observed exaggerated growth of the hybrid and his disproportionately large extremities are due to a glandular disturbance of genetic origin." He also attributed the higher rate of diabetes to errors in hormonal regulation.


After

There were no subsequent studies. It would be easy to say that research ended with the widespread revulsion against Nazi Germany in 1945. Actually, the end came earlier, in the 1930s with the triumph of Boasian anthropology and behaviorist psychology. Both stressed the plasticity of the human mind and shifted the focus of research from nature to nurture, i.e., to "society" and possibilities for social change. 

Nonetheless, even within academia, important people continued to voice support for hereditarian and eugenic positions. John Maynard Keynes served as the director of the Eugenics Society of London (1937-1944) and in 1946 was still calling eugenics "the most important and significant branch of sociology" (Brignell 2010). The science fiction series Star Trek ran an episode in 1967 on eugenics ('Space Seed'). The Eugenics Review would be renamed The Journal of Biosocial Science only in 1969. Eugenic laws remained on the books and were enforced as late as the 1970s in some jurisdictions. 

All of this may seem surprising because there has been an effort to push the systematic rejection of eugenics farther and farther back in time. The Wiki entry on Charles Davenport, for instance, states that "only his ardent admirers" took his research seriously. The truth is that he was widely respected until the 1930s. His 1911 work, Heredity in Relation to Eugenics, became a college textbook (Wikipedia 2020). Mjøen was likewise well regarded:

His fame was such that he was one of three expert advisors consulted by the US Congress in the appointment of the first President of the American Eugenics Society, he gave a lecture tour of eighteen American universities in 1927, and, in a period in which The New York Times voiced anxieties about the future of the 'Nordic Type' in America, the newspaper of record invoked Mjøen repeatedly (Reinert 2015)

Even on the left, the general attitude was cautious acceptance, as seen in this 1928 report from the Eugenic Society of Leningrad:

P. I. Ljublinsky remarked that there was not much to be said for the two extreme views of this problem—the doctrine of complete indifference to the matter and the system of strict measures. Therefore what must be recognised as most advantageous is something lying between the two extremes,—a certain system of compromise, of which he himself was an adherent. The meeting gave its support to this last standpoint. It was decided that certain legislative prohibitions in this field are undoubtedly of service. (Philiptschenko 1928)

On the specific issue of outbreeding, feelings were more mixed:

After the conclusion of the discussion the meeting decided that, although the question of race crossing is very important, it is difficult to regard is as definitely solved. But in contrast to the attitude adopted in the Norwegian programme it must be stated that, so long as we have no other data available, we cannot express an opinion against the crossing of different races and nations. (Philiptschenko 1928)

There would be no more data. The Soviet Union, like the world in general, looked up to progressive thought in the West, particularly in the United States. By the 1930s, the shift toward blank slate thinking had become overwhelming among American intellectuals.


Conclusion

If we go back to the recent studies on fertility and outbreeding, we see that fertility progressively declines when outbreeding takes place beyond one's fourth cousin. A growing proportion of embryos or fetuses fail to develop beyond a certain point, apparently because of some incompatibility.

Outbreeding depression seems to be a real phenomenon, but how serious is it? Davenport examined perhaps the maximum degree of outbreeding possible, and only a minority of individuals showed a degree of dysfunction that was higher than expected. The proportion varied according to the mental test, from a low of about 5% to a high of 30%. It is likely that subsequent generations would show progressively lower proportions, with natural selection removing the least functional individuals through reduced fertility, inability to find a mate, or higher risk of illness. 

Davenport was cautious in interpreting his results, noting the difficulty in estimating the size of the adverse outbreeding effect. His self-criticism was taken up by his critics, and the current prevalent view is that his study has been thoroughly discredited, if not by methodological problems, then by Hitler.


References

Brignell, V. (2010). The eugenics movement Britain wants to forget. New Statesman. December 9 http://www.newstatesman.com/society/2010/12/british-eugenics-disabled 

Davenport, C.B. and M. Steggerda: (1928). Race Crossing in Jamaica. Washington: Carnegie Institution, Publication no. 395.
http://www.velesova-sloboda.info/archiv/pdf/davenport-race-crossing-in-jamaica.pdf

Helgason, A., S. Pálsson, D.F. Guðbjartsson, þ. Kristjánsson, K. Stefánsson. (2008). An association between the kinship and fertility of human couples. Science 319(5864): 813-816.
http://facelab.org/debruine/Teaching/EvPsych/files/Helgason_2008.pdf

Labouriau, R., and A. Amorim. (2008). Comment on "An Association Between the Kinship and Fertility of Human Couples" Science 322(5908): 1634
http://science.sciencemag.org/content/322/5908/1634.2.full

Mayr, E. (1970). Populations, Species, and Evolution. Cambridge (Mass.): Belknap Press.

Mjøen, J.A. (1931). Race-crossing and glands. Some human hybrids and their parent stocks. The Eugenics Review 23(1): 31-40.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984998/?page=1

Philiptschenko, J.A. (1928). The Norwegian eugenic programme discussed at meetings of the eugenic society of Leningrad. The Eugenics Review 19(4): 294-298.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984720/

Reinert, S.A. (2015). The economy of fear:  H.P. Lovecraft on eugenics, economics and the Great Depression. Horror Studies 6(2): 255-281.
https://www.academia.edu/19676748/The_Economy_of_Fear_H.P._Lovecraft_on_Eugenics_Economics_and_the_Great_Depression

Wikipedia. (2020). Charles Davenport.
https://en.wikipedia.org/wiki/Charles_Davenport

Monday, January 6, 2020

The 2020s are here



Elderly Shanghai woman practicing tai-chi (Wikipedia – Tom Thai)



Two years ago I wrote about "The Crisis of the 2020s." I argued that this decade would see a worsening confrontation between two world views:

On the one hand, the globalist consensus will continue to radicalize in the core countries of the Western world. On the other hand, a very different consensus will dominate most of central and eastern Europe, with inroads being made into France and Germany. These opposing consensuses will diverge more and more, if only because mutual antagonism will make dialogue impossible. (Frost 2017a)

This confrontation is taking place at a time when the "consensus" no longer seems to be delivering the goods. Economic growth is sluggish not only throughout the West but also in the supposed beneficiaries of globalization—China, in particular. For some, this slowdown means that the current system has failed. For others, it means that the failings of globalization can be resolved only through more globalization.

The Crisis of the 2020s is thus primarily ideological. People are split into opposing camps, and it is far from clear which one will win. While the globalist consensus is losing ground in eastern, central, and southern Europe, it still dominates the western core of the UK, France, and Germany ... as well as North America. The West has lost its manufacturing base but is still culturally dominant. That dominance, not so much in ideas as in the packaging of ideas, is critical to promoting a model of society where people are interchangeable units in a global marketplace.

The ideological crisis will nonetheless be made worse by real-world problems:


China: a shrinking work force

China’s exports will become more expensive as its work force shrinks and grows old. This shrinkage will be worse than expected because the Chinese authorities have been overestimating the country’s fertility rate for almost two decades. The current rate is not 1.6 children per women. In fact, it had already fallen to 1.4 by 2003 and is now probably one child per woman. And this is happening even though the one-child policy is no longer in effect. The fertility rate is even lower among Han Chinese and lower still in the industrialized northeast—where it is down to 0.75 (Frost 2019a; Wang 2018). 

There are already fewer Chinese workers with each passing year, and this decrease will accelerate as the smaller cohorts of the noughts and teens enter the job market. Inevitably, the price of labor will rise. This will be good for China, which needs to reorient away from exports and toward its domestic economy. Western countries, however, will have to be weaned off their dependence on cheap Chinese goods.

Can the same goods be produced elsewhere? Unlikely. None of the alternatives sources of cheap labor have the same worker quality or, just as importantly, worker quantity. In hindsight, China was a lucky find for globalization—a country where the average worker was not only inexpensive but also intelligent and disciplined.

Western consumers are already cash-strapped, with most of them living from pay check to pay check. Where will they get the money to pay for a steep increase in the price of consumer goods?


The global food crisis

The Arab Spring was triggered by a surge in food prices. That surge was no fluke. We are reaching the end of a long increase in food production, a “green revolution” made possible by large-scale monoculture, intensive plowing, and heavy use of chemical fertilizers. That increase has come at a price, particularly degradation of soil fertility. Further increases will be modest and will require a more sustainable model of agriculture, as well as more investment in automation and robotization. Unfortunately, such changes, especially the latter, are impeded by the current heavy reliance on cheap migrant labor.

Agribusiness, particularly in the U.S., has become a conservative force that will stubbornly resist change. Like the culture industry, it will push for more of the same.


The decline of high-trust societies

The evolution of social complexity is far from easy. One of the main challenges has been the creation of large societies in which economic transactions take place mostly between unrelated individuals. Such societies are impossible in most of the world because of the high level of mistrust between unrelated individuals. Each transaction has to be checked and double-checked for lying, cheating, and outright theft. Many transactions never take place because they just aren't cost-effective.

This obstacle has been overcome in northwest Europe and East Asia. In both areas, the solution is behavioral and psychological. Northwest Europeans are more individualistic, less loyal to kin, and more trusting of strangers. Because they attach less importance to kinship, they have been able to build large, functioning societies on the basis of “impersonal prosociality,” i.e., willingness to obey universal social rules, affective empathy toward nonkin, and feelings of guilt for unwitnessed rule breaking (Frost 2017b; Frost 2019b; Schulz et al. 2019). East Asians are less individualistic but just as willing to obey universal rules, which are enforced more by shame than by guilt. Empathy is also at a high level, but less differentiated between affective and cognitive empathy:

The main difference is in the relationship between self and society. Whereas a greater sense of self has helped Northwest Europeans to transcend the limitations of kinship and, thus, build larger societies, East Asians have relied on a lesser sense of self to create a web of interdependence that extends beyond close kin. (Frost 2015)

Northwest Europeans and East Asians are now in steep demographic decline. Inevitably, less wealth will be created. I say "inevitably" because those two groups produce most of the world’s wealth. When they go, most of the wealth will go too. This is not a problem we can resolve by passing laws or changing the school curriculum. To some extent, we could force people to adopt the behaviors of a high-trust society, but that would take time and will. And we don't have much of either.


A name with a nice ring to it

When I wrote that post two years ago I settled on the name "Crisis of the 2020s." It had a nice ring to it. While doing research for this post, I googled the same name ... and got over 56,000 hits. The oldest hit seems to be a 2011 article: "Global Aging and the Crisis of the 2020s." I hadn't read it previously, but it points to the same underlying problem:

The working-age population has already begun to contract in several large developed countries, including Germany and Japan. By 2030, it will be stagnant or contracting in nearly all developed countries, the only major exception being the United States. In a growing number of nations, total population will begin a gathering decline as well. Unless immigration or birthrates surge, Japan and some European nations are on track to lose nearly one-half of their total current populations by the end of the century. (Howe and Jackson 2011)

That article differs from mine in its implied advocacy of immigration as a solution. To be sure, it does mention "the lawlessness of immigrant youths in large cities [of Western Europe]," but it remains upbeat about the United States "because of its higher fertility rate and because of substantial net immigration, which America assimilates better than most other developed countries" (Howe and Jackson 2011). That optimism was already exaggerated in 2011. Today, mass immigration is just as much a process of cultural and demographic replacement in the U.S. as it is in Western Europe.

Let's be frank. The high productivity of North America, Western Europe, and East Asia has profound behavioral and psychological causes. It is not due to political ideals, universal education, or a particular legal system. It is due to a higher level of social trust, as well as a higher level of cognitive ability and a lower level of personal violence. When immigrants enter that kind of environment, their productivity dramatically rises. They are now working in a society where laws are observed, where information is reliable, and where disputes are not normally settled through violence. We all benefit from that kind of society—simply by virtue of living in it.

That’s the "unearned privilege" that antiracists and right-wing economists love to denounce. Their argument is deceptively simple: “By what right do we deny this privilege to others?  It’s a mere accident of birth! Just think, they’re less productive because we’re keeping them out. So let them in! We’ll all be better off!”

Well, no. Do I have to explain why? 


References

Frost, P. (2015). Two Paths. The Unz Review, January 24
https://www.unz.com/pfrost/two-paths/

Frost, P. (2017a). The Crisis of the 2020s. Evo and Proud, December 19.
http://evoandproud.blogspot.com/2017/12/the-crisis-of-2020s.html

Frost, P. (2017b). The Hajnal line and gene-culture coevolution in northwest Europe. Advances in Anthropology 7: 154-174.
https://file.scirp.org/pdf/AA_2017082915090955.pdf 

Frost, P. (2019a). Autumn in China. Evo and Proud, March 26
http://evoandproud.blogspot.com/2019/03/autumn-in-china.html 

Frost, P. (2019b). Was Western Christianity a cause or an effect? Comment on: J.F. Schulz, D. Bahrami-Rad, J.P. Beauchamp, and J. Henrich. The Church, intensive kinship, and global psychological variation. Science 366 (6466)
https://science.sciencemag.org/content/366/6466/eaau5141/tab-e-letters  

Howe, N., and R. Jackson. (2011). Global aging and the Crisis of the 2020s. Current History, January, pp. 20-25
https://pdfs.semanticscholar.org/9879/fe3ea41e85f5fdfb6bc1ffcc2ae5c44a1a2a.pdf 

Schulz, J.F., D. Bahrami-Rad, J.P. Beauchamp, and J. Henrich. (2019). The Church, intensive kinship, and global psychological variation. Science 366(707): 1-12. 
https://web.ics.purdue.edu/~drkelly/SchulzHenrichetalTheChurchIntensiveKinshipGlobaPsychologicalVariation2019.pdf

Wang, M. (2018). For Whom the Bell Tolls: A Retrospective and Predictive Study of Fertility Rates in China (November 8, 2018). Available at SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3234861  

Monday, December 23, 2019

Not what you think



Preparing for a test (Wikicommons - Excelz)



Why do West African immigrants outperform native-born whites in UK schools? This is the question posed by Chanda Chisala using data from the GCSE, the General Certificate of Secondary Education. 

To be sure, the GCSE is not the same as an IQ test. For most subjects it includes things like coursework and attendance. The test-taker is also motivated by self-interest: a high GCSE score can be a ticket to a good university and a good job. Nonetheless, Thompson (2013) has argued that the GCSE has a correlation of 0.81 with IQ. So perhaps the two are roughly equivalent.

Let's look at the GCSE results from England for 2012. They are indeed astounding for immigrant children from English-speaking Africa. Just look at the percentage difference from the mean by country of origin:

Nigerians -     +21.8
Ghanaians -     +5.5
Sierra Leone - +1.4

Source: Chisala (2019)

This academic excellence seems to be unusually concentrated among Nigerian immigrants. Are we looking at our friends from the Niger delta? Often known as the "Jews of West Africa," the Igbo have a long record of academic and economic success. This has been attributed to their openness to Western learning and the commercial opportunities it creates, although the Igbo were, in fact, a trading nation long before the colonial era (Frost 2015). They became receptive to Western learning because they had long been receptive to learning in general, much like the Japanese during the Meiji era.

Chisala (2015) provides an ethnic breakdown of GCSE results for the years 2009 to 2011:

2009: Igbo - 100%, Yoruba - 39%
2010: Igbo - 80%, Yoruba - 68%
2011: Igbo - 76%, Yoruba - 75%

The Igbo started off as top achievers, but their lead evaporated over the next two years as the Yoruba made remarkable gains. There were 90 Yoruba kids, so sampling error could hardly explain their increase from 39% to 75%. Because the Igbo kids numbered only 16, the decrease from 100% to 76% might not be significant.

Perhaps the Yoruba kids got better coaching and tutoring. Whatever the explanation, GCSE cannot be used as a proxy for IQ, at least not for Nigerians. Yes, IQ can change over the course of a lifespan, but not that fast and not that much—unless you suffer a serious accident.


Exam malpractice

There are less innocent explanations for the rapid rise in Yoruba scores. A study of students in Nigeria found that test-retest reliability ranged from 77 to 85% (Petters and Okon 2014). The authors blame the low test reliability on cheating, calling it "a plague":

Examination malpractice in Nigeria has attained a frightening proportion and it is becoming more sophisticated as years pass by. Efforts by government and stakeholders to curtail this trend have not yielded much success. If this trend is not given an urgent attention, it may utterly destroy the quality of education in Nigeria.

Bisong et al. (2009) come to similar conclusions:

The implication of this study is that the cheating tendency is becoming endemic in Nigerian society. A situation where one in every four students tends to cheat in every examination calls for a significant moral questioning of our society. Even with a high level of supervision, as the results show, students are still prone to indulge in cheating behaviour.

In their review of the literature, Bisong et al. (2009) note that "in 1980, out of the 190,000 candidates who sat the West African Examination Certificate in May and June, 46,000 candidates from Nigeria had their results nullified." Cheating is partly due to Nigerian parents, who understand the value of academic success and push their children to get good grades "by all means":

Parents expect nothing less than passing in examination from their children. There must not be failure. That is to say that he who fails is not entertained in any way. Where there is weakness or a psychological measure that one is not prepared to pass the examination, then fear begins to disturb the minds of students as to how to make it. This leads to serious reading throughout the night, pressing lectures for areas of concentration and arranging to enter the examination hall with every possible means to cheat during the examination. (Halima 2003, p. 17)

Halima (2003, p. 19) notes the harshness of penalties for cheating: "in 1983 the punishment for cheating was increased to a jail term of 21 years without the option for fine. In spite of this cheating in examination increased."


Nigeria's cognitive elite?

It has been argued, notably by Greg Cochran, that Nigerian immigrants are skimmed from the top of their country's IQ distribution (Cochran 2019). They are the best that Nigeria has to offer—la crème de la crème. To make that argument work, however, Nigerian immigrants to the UK would have to be much smarter than the average Nigerian, with an IQ more than one standard deviation higher and probably two.

There is only a rough consensus on the mean IQ of sub-Saharan Africa. In their review of the literature, Wicherts et al. (2010) argue for a mean of 82, whereas Lynn (2010) puts it at 66. Rindermann (2013) favors a "best guess" of 75. Even if we take the high estimate of 82, we must still assume extreme selection to get a mean IQ above 100. Is that a reasonable assumption?  Elite individuals exist among immigrants from Nigeria, but they are not the majority: 

Socially, the Nigerian diaspora is by no means homogenous. There are those who struggle for basic means of survival such as car park attendants, cleaners and other menial workers working long hours to make ends meet. But some professionals have distinguished themselves and moved on to become members of the Black middle class. (Akinrinade and Ogen 2011)

Furthermore, some doubt may be cast on the credentials of middle-class Nigerians: "they have acquired a notorious reputation for arrogance and fraud" (Akinrinade and Ogen 2011). Finally, the cognitive elite argument fails to explain why immigrants from Nigeria do so much better than those from Ghana and Sierra Leone.


Math scores

On many GCSE components, there is much room for cheating, particularly on coursework. But what about the mathematics component? GCSE math has not had coursework since 2009. It is simply a timed test. How can one cheat on a timed test?

By impersonation. A "ghost" who knows the subject takes the exam by impersonating the student, and the actual student never takes the exam (Azuka 2014). This method requires a photo ID that combines the ghost's photo with the test-taker's name. In most cases, the fake ID is sufficient to dispel any suspicions.


Conclusion

For whatever reason, the GCSE is too volatile to be used as a proxy for IQ, particularly in the case of Nigerian students. The volatility seems to be due to cheating, as well as to the grey area of coaching and tutoring services. Cheating is rife among Nigerians in Nigeria, and it would be naïve to suppose that such behavior disappears once they relocate to another country, especially if their new country imposes none of the harsh penalties that are regularly imposed in Nigeria.

Nigerian academic achievement may be genuine in some cases. This is particularly so with respect to the Igbo, who have a longstanding record of achievement within and outside school. Unfortunately, genuine ability can be cofounded with fake ability. Smart people are better at gaming the system and making themselves look smarter than they really are.

Indeed, I can't help wondering when I look at the GCSE results for Igbo students in 2009. Every single Igbo got a perfect score—that's unusual even for a smart population and even with a sample size that small. Chanda suggests that year-to-year fluctuations might have made the sample even smaller in that year. Well, perhaps.

It would be easy to say that we need more data. Additional GCSE results, however, will be just as distorted by academic fraud. We need data from real IQ tests that provide no incentive for cheating.


References

Akinrinade, S., and O. Ogen. (2011). Historicising the Nigerian Diaspora: Nigerian Migrants and Homeland Relations. Turkish Journal of Politics 2(2): 71-85.
https://s3.amazonaws.com/academia.edu.documents/31034426/tjp_sayi_4.pdf?response-content-disposition=inline%3B%20filename%3DTurkish_Journal_of_Politics_TJP_V._2_N..pdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWOWYYGZ2Y53UL3A%2F20191221%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20191221T170342Z&X-Amz-Expires=3600&X-Amz-SignedHeaders=host&X-Amz-Signature=033191eb3309b04839db9b399a1976750b779991740778b6044b92573f0b1501#page=73

Azuka, E.B. (2014). Academic Fraud among Students in Higher Education in Nigeria: Reasons, Methods Adopted and Strategies to curb it. Journal of Educational and Social Research 4(3): 289-296.
https://www.mcser.org/journal/index.php/jesr/article/view/2725 

Bisong, N.N., F. Akpama, and P.B. Edet. (2009). Cheating Tendency in Examinations among Secondary School Students in Nigeria:  a case study of schools in the Odukpani Local Government Area, Cross River State. Policy Futures in Education 7(4): 410-415
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1030.3426&rep=rep1&type=pdf  
Chisala, C. (2019). Why Do Blacks Outperform Whites in UK Schools? The Unz Review, November 29
https://www.unz.com/article/reply-to-lance-welton-why-do-blacks-outperform-whites-in-uk-schools/?showcomments#comments 

Chisala, C. (2015). UK: Igbo Nigeria Academic performance destroys the myth of Black Low IQ. Afripol November 28
http://afripol.org/afripol/item/1813-uk-nigerian-academic-performance-in-destroys-the-myth-of-black-low-iq.html

Cochran, G. (2019). Selective immigration. West Hunter, March 13
https://westhunt.wordpress.com/2019/03/13/selective-immigration/

Frost, P. (2015). The Jews of West Africa? The Unz Review, July 4
https://www.unz.com/pfrost/the-jews-of-west-africa/ 

Halima, D. (2003). A study of some socio-psychological factors of cheating in examination among students of Kaduna Polytechnic. Post Graduate School Ahmadu Bello University Zaria.
http://kubanni.abu.edu.ng/jspui/bitstream/123456789/2190/1/A%20%20STUDY%20OF%20SOME%20SOCIO-PSYCHOLOGICAL%20FACTORS%20OF%20CHEATING%20IN%20EXAMINATION%20AMONY%20STUDENTS%20OF%20%20KADUNA%20POLYTECHNIC.pdf 

Lynn, R. (2010). The average IQ of sub-Saharan Africans assessed by the Progressive Matrices: A reply to Wicherts, Dolan, Carlson & van der Maas. Learning and Individual Differences 20(3): 152-154.
https://www.sciencedirect.com/science/article/pii/S1041608010000348

Petters, J.S., and M.O. Okon. (2014). Students' Perception of Causes and Effects of Examination Malpractice in the Nigerian Educational System: The Way Forward for Quality Education. Procedia - Social and Behavioral Sciences 114: 125-129
https://www.sciencedirect.com/science/article/pii/S187704281305310X

Rindermann, H. (2013). African cognitive ability: Research, results, divergences and recommendations. Personality and Individual Differences 55: 229-233.
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.372.5462&rep=rep1&type=pdf

Thompson, J. (2013). IQ and GCSE Results in England R=0.81. The Unz Review, November 5
https://www.unz.com/jthompson/iq-and-gcse-results-in-england-r081/ 

Wicherts, J.M., C.V. Dolan, and H.L.J. van der Maas. (2010). A systematic literature review of the average IQ of sub-Saharan Africans. Intelligence 38: 1-20.
http://www.iapsych.com/iqmr/fe/LinkedDocuments/wicherts2010b.pdf