Tuesday, March 30, 2021

Recent cognitive evolution in West Africa


If we look at alleles associated with higher educational attainment, we find more of them among the Yoruba of Nigeria than among the Mende of Sierra Leone. The reason may be differences in social evolution over the past 1,000 years, particularly in trade, urban settlement, State formation, and other forms of social complexity. 

Ife king's head (14th or early 15th century) (Wikicommons - Vassil)



How can we measure the genetic component of cognitive ability? We have long used IQ tests to get a rough idea, but they are not an ideal yardstick. Twin studies have shown that genetic factors explain about two thirds of the variance in IQ results, perhaps even less for comparisons between people of different cultural backgrounds.


In recent years we've found a new yardstick: the polygenic score. It's a more direct genetic measurement, being a summation of alleles that have been linked to higher educational attainment. As a method for estimating the mean cognitive ability of a population, it seems to be as good as IQ tests. Piffer (2019) found a 90% correlation between the two methods. In his latest study, he has again found the same correlation (Piffer 2021, see Figure 8).


Interestingly, that study shows differences in mean cognitive ability within West Africa: the Mende of Sierra Leone score much lower than the Yoruba of Nigeria. In fact, the Yoruba have almost the same polygenic score as do African Americans, even though the latter have about 20% European admixture. Unfortunately, we have no data on the Igbo of Nigeria, who are known to be high achievers at school and in other areas of life (Frost 2015).


These differences within West Africa support the argument that mean cognitive ability has continued to increase in some human populations, even in relatively recent times. With respect to the Yoruba, their cognitive ability may have increased in tandem with their advances in trade, urban settlement, and State formation from the tenth century onward (Akintoye 2014; McIntosh and McIntosh 1988). Meanwhile, the Mende remained at a lower level of social complexity.


There is one problem with using polygenic scores for West Africans, or for any non-European population. To identify alleles associated with higher educational attainment, researchers have used genomes of European origin. There is evidence, however, that the architecture of cognitive ability may differ in different human populations. The same alleles might not explain high cognitive ability in West Africans and Europeans. Indeed, Lasker et al. (2019) found a lower correlation between polygenic scores and cognitive ability in African Americans than in European Americans.




Akintoye, S.A. (2014). A History of the Yoruba People. Dakar: Amalion.


Frost, P. (2015). The Jews of West Africa. The Unz Review, July 4



Lasker, J., B.J. Pesta, J.G.R. Fuerst, and E.O.W. Kirkegaard. (2019). Global ancestry and cognitive ability. Psych 1(1)



McIntosh, S.K., and McIntosh, R.J. (1988). From stone to metal: New perspectives on the later prehistory of West Africa. Journal of World Prehistory 2: 89-133. https://doi.org/10.1007/BF00975123  


Piffer, D. (2019). Evidence for Recent Polygenic Selection on Educational Attainment and Intelligence Inferred from Gwas Hits: A Replication of Previous Findings Using Recent Data. Psych 1(1): 55-75. https://doi.org/10.3390/psych1010005  


Piffer, D. (2021). Divergent selection on height and cognitive ability: evidence from Fst and polygenic scores. OpenPsych


Monday, March 22, 2021

The big bird that takes away water


The constellation of the Southern Cross has inspired similar myths among indigenous peoples as far apart as Australia and South America. Why?

Southern Cross (Wikipedia – Yulanlu97). 



Did people cross the Pacific in pre-Columbian times? This question has aroused renewed interest with the discovery of sweet potato remains at Polynesian sites dated to A.D. 1000. There also seem to be loan-words of Polynesian origin in some Amerindian languages (Jones et al. 2011). Finally, we have strong evidence that Polynesians introduced chickens to the west coast of South America in prehistoric times, probably A.D. 1300-1420 (Fitzpatrick and Callaghan 2009).


A new piece of evidence is the similarity between a myth told by Aboriginal Australians, particularly those of southeast Australia, and a myth told by indigenous peoples in Argentina and central Brazil. In both cases, one finds the same two elements:


- A large flightless bird that can cause the land to dry up.

- The constellation of the Southern Cross and two adjacent regions of the sky: the Southern Pointers (Alpha and Beta Centauri) and the Coalsack Nebula


These similarities are mentioned by Gullberg et al. (2020) in a cross-cultural study of beliefs about the 'Dark Constellations':


Wiradjuri, Kamilaroi, Euahlayi, and others (Australia)


The Emu in the Sky is perhaps the best-known Aboriginal dark constellation (Figure 2). It is the silhouette of an emu traced out by the dark nebulae within the plane of the Milky Way and is featured in the traditions of Aboriginal people across Australia. The Coalsack Nebula, near the Southern Cross, forms the head, and the body extends along the dust lanes through Centaurus in the Milky Way, to the body as outlined by the galactic bulge in Scorpius and Sagittarius (Gullberg et al. 2020, p. 392)


When the celestial emu swings to where it is low on the horizon in October and November, the galactic bulge is now seen as the backside of an emu sitting in a waterhole, displacing the water and causing the land to dry up as the hot summer months approach. (Gullberg et al. 2020, p. 393)


Moqoit (Argentina)


Due to this crucial role of the Milky Way and the fact that it is a huge area of diffuse brightness interrupted by dark spots, it is not surprising that the Moqoit pay attention to dark patterns on it. The most important of all of them is the Mañic, the master of the South American rheas, a large flightless bird similar to an emu or ostrich shown in (Figure 5)


[…] We know many Moqoit stories mention that in the time of the origins, the master of Mañic used to shelter in a number of burrows, under the roots of an ombú (a very big tree, seen as the world tree—the Milky Way), and eat humans. Lapilalaxachi, a powerful human ancestor of the Moqoit people identified with the Pleiades, decided to face the Mañic. He chased the Mañic throughout the world and the cornered Mañic climbed up the ombú trunk to the sky.


Today, the shadow-soul (la 'al) of the Mañic can be seen in the Milky Way's dark clouds, with its head in what we know as the Coalsack (around -59° 50' galactic longitude). Alpha and Beta Centauri are the dogs of the man chasing the Mañic and bite at its neck (López and Giménez-Benítez, 2008). The Mañic's head is the Coalsack.

(Gullberg et al. 2020, p. 396)


Tupi (central Brazil)


In a similar view, the Tupi people of central Brazil also perceive a rhea in the sky, making essentially the same shape as the Aboriginal emu. The rhea and the emu are both large, flightless birds with a similar appearance and breeding cycle. Just as in Moqoit traditions, the head of the rhea is the Coalsack, and the body is traced out by dust lanes in Centaurus and Scorpius. The Tupi associate the rhea with the end of the world. The stars of Crux are holding the head of this animal. If it escapes, it will drink all the water of the world (Alencar, 2011)

(Gullberg et al. 2020, p. 397)



Why is this myth found only in Australia and South America? Why is it absent in-between? Actually, a version does exist on the Polynesian island of Tonga, except that the large flightless bird is a giant duck and it simply keeps people from getting access to water:


Tongans (Polynesia)


Polynesians of the Pacific recognise dark spaces in the Milky Way, focusing on the Coalsack Nebula and relating it to fish or fishing. Polynesian traditions of Tonga describe it as Humu (a giant triggerfish). In their traditions (Gifford, 1924), a Tongan chief named Ma'afu took a lizard wife and had twin sons, which they wanted gone as the chief's subjects were afraid of the pair. Ma'afu sneakily instructed the brothers to collect water from a waterhole containing a giant duck that would kill and consume anyone who came too close. The boys were attacked by the duck but grabbed it by the neck and killed it. When the boys returned unharmed, the father instructed them to obtain water from a more distant waterhole, inhabited by Humu, a triggerfish (these are large aggressive animals with powerful teeth designed for crushing shellfish). The boys killed the triggerfish and in anger at this, the father blurted out his secret to have the boys killed. The boys walked away and ascended to the stars, each carrying one of the two animals they killed. The twins became the Magellanic Clouds, the duck became the Southern Cross (with the duck's bill as γ Crucis), and Humu became the Coalsack Nebula

(Gullberg et al. 2020, p. 398)



My thoughts


This myth seems to have begun in one of three areas (Australia, Polynesia, South America) and then spread to the other two. If it began among Aboriginal Australians, the myth could be very old, going back perhaps 65,000 years. If it began among the Amerindian peoples of South America, it may go back 10,000 years. Finally, if it began among the Polynesians, the time depth would be no more than 3,500 years. The first and last scenarios seem most likely, given that oceanic travel was much easier from Polynesia to South America than the reverse (Fitzpatrick and Callaghan 2009).


Nonetheless, all of the scenarios run into a big problem: the myth is known to South American groups on the east side of the continent but not to those on the west side (which would be more consistent with trans-Pacific contact). I can think of only one other scenario. Given that the Americas were once inhabited by a population related to Aboriginal Australians and similar groups in Southeast Asia (Frost 2015), the myth may have originated in Asia more than 65,000 years ago and then spread in two directions: to Australia via Southeast Asia and to the Americas via the Bering Strait. But could a myth survive intact for that long?


Two other things leave me wondering. Why would the sky around the Southern Cross be seen as a large flightless bird? Gullberg et al. (2020) provide several pictures of that part of the sky and trace the outline of a bird on them. To my eyes, one could just as easily trace the outline of many other animals.


Finally, is this evidence, à la Von Däniken, of extraterrestrial contact? Keep in mind that the region of the Southern Cross includes the closest star system to ours. And if that system does have intelligent life, should we be reaching out to them and inviting them over? The last time around they didn’t leave a good impression.


Enough! I shouldn’t let myself get carried away. Extraordinary claims require extraordinary evidence, and a single myth hardly qualifies as extraordinary.





Fitzpatrick, S.M. and R. Callaghan. (2009). Examining dispersal mechanisms for the translocation of chicken (Gallus gallus) from Polynesia to South America. Journal of Archaeological Science 36(2): 214-223.



Frost, P. (2015). Guess who first came to America? Evo and Proud. August 1



Gullberg, S.R., D.W. Hamacher, A. Martin-Lopez, J. Mejuto, A.M. Munro, and W. Orchiston. (2020). A Cultural Comparison of the 'Dark Constellations' in the Milky Way. Journal of Astronomical History and Heritage 23(2): 390-404.



Jones, T.L., A.A. Storey, E.A. Matisoo-Smith, and J.M. Ramirez-Altamira (eds). (2011). Polynesians in America: Pre-Columbian Contacts with the New World. Rowman Altamira.

Monday, March 15, 2021

Nigerians, Scrabble, and the GCSE


Exam hall at Hull Collegiate School (Wikicommons – Robin S. Taylor). The GCSE exam is a poor measure of raw cognitive ability. If some students get tutored and others do not, there will be more environmental variance in IQ, and the exam results will say less about the genetic potential for cognitive ability.



Chanda Chisala has written more about cognitive ability in sub-Saharan Africa. His argument is straightforward:


[…] if it is true that on average black Africans in Africa score extremely low on scholastic/intelligence tests because they grow up with much less educational and other modern cultural resources (as Flynn would agree), then they should perform "extremely well" (by comparison) in those "g-loaded" cognitive contests that do not require too much of such quality cultural exposure (as Jensen would agree). (Chisala 2021)


Chanda argues that raw cognitive ability is better measured in Africa by a Scrabble championship than by an IQ test, since most Africans lack "access to well-trained teachers, big libraries, computers or even TVs" (Chisala 2021). Africans are good at Scrabble:


Nigeria happens to be the world's top performing nation in English Scrabble, while francophone African countries are also the most dominant in French Scrabble, despite the fact that the top players in Western countries are super-high-IQ nerds with visibly exceptional mathematical talents (Chisala 2021)


Correlation isn't causation. Is a high IQ needed to do well at Scrabble? Not according to this study:


Forty tournament-rated SCRABBLE players (20 elite, 20 average) and 40 unrated novice players completed a battery of domain-representative laboratory tasks and standardized verbal ability tests. The analyses revealed that elite- and average-level rated players only significantly differed from each other on tasks representative of SCRABBLE performance. Furthermore, domain-relevant practice mediated the effects of SCRABBLE tournament ratings on representative task performance, suggesting that SCRABBLE players can acquire some of the knowledge necessary for success at the highest levels of competition by engaging in activities deliberately designed to maximize adaptation to SCRABBLE-specific task constraints. (Tuffiash, Roring, and Ericsson 2007)


Success at Scrabble seems to be due largely to practice and is thus a poor measure of raw cognitive ability.


A curious detail: Nigeria's top performers come overwhelmingly from one part of the country: the Niger Delta, which is home to the Igbo and related tribes. Since the peoples of the Niger Delta used to dominate trade between the coast and the interior, and since trade selects for cognitive ability, mean IQ should be higher in those populations that have long practiced it, like the Igbo (Frost 2015).


Young Nigerians in the UK - Academic achievement on the GCSE


Although many African immigrants do poorly in British schools, some actually do well. A study of six secondary schools in inner London found that results on the General Certificate of Secondary Education (GCSE) were higher for African students who spoke Igbo, Yoruba, Luganda, and Ga than for White British students who spoke only English (Demie 2013, p. 9). Chanda sees the GCSE as a proxy for IQ and argues that IQ differences between African immigrants and White British must be highly malleable:


Africans speaking Luganda and Krio did better than the Chinese students in 2011. The igbo were even more impressive given their much bigger numbers (and their consistently high performance over the years, gaining a 100 percent pass rate in 2009!). The superior Igbo achievement on GCSEs is not new and has been noted in studies that came before the recent media discovery of African performance. A 2007 report on "case study" model schools in Lambeth also included a rare disclosure of specified Igbo performance (recorded as Ibo in the table below) and it confirms that Igbos have been performing exceptionally well for a long time (5 + A*-C GCSEs); in fact, it is difficult to find a time when they ever performed below British whites. (Chanda 2015)


Igbo students stood out as high achievers on the GCSE, as did Yoruba students to a lesser extent. In both groups, however, the mean results were highly variable from one year to the next:


2009: Igbo - 100%, Yoruba - 39%

2010: Igbo - 80%, Yoruba - 68%

2011: Igbo - 76%, Yoruba - 75% 

(Demie 2013, p. 9)


Chanda attributes this variability to statistical noise caused by small sample size. If so, there should be an inverse correlation between sample size and variability. GCSE scores should be more variable for smaller groups than for larger ones. Yet the reverse seems to be true for the years 2009 to 2011:


Yoruba: 90 students / gain of 36 percentage points

Somali: 53 students / gain of 13 percentage points

Twi-Fante: 37 students / loss of 3 percentage points

Igbo: 16 students / loss of 24 percentage points

Krio: 12 students / gain of 4 percentage points

Tigrinya: 12 students / loss of 8 percentage points

Lingala: 12 students / loss of 5 percentage points

Ga: 8 students / gain of 9 percentage points

Swahili: 8 students / gain of 10 percentage points 

(Demie 2013, pp. 7, 9)


The two largest gains were made by the two largest groups: the Yoruba and the Somali. If the differences between 2009 and 2011 are statistical noise, why are the largest ones associated with the largest groups? Shouldn't we see the reverse? Shouldn't the smallest groups show the most variability?


Something seems to be causing those impressive GCSE gains. Since the students are not the same from one year to the next, and since the gains differ considerably from one ethnic community to another, the "something" must be the community itself. Over time, the Yoruba community became better at assisting its students, and this kind of assistance was available only in larger communities like the Yoruba.


The most obvious forms of assistance are tutoring and coaching. Such assistance is mentioned by parents in interviews for the above study:


Parent A: Father of daughter in Year 9. Generally supportive of the school which was not his first choice but is supplementing his daughter's education with a home tutor. He also calls on his extended family, his oldest son who is a graduate is also expected to help. (Demie 2013, p. 14)


Although tutoring and coaching are perfectly legitimate, they invalidate the GCSE as a means to measure IQ, particularly its genetic component. If some students get tutored and others do not, there will be more environmental variance in IQ, and the exam results will say less about the genetic potential for cognitive ability. Therefore, GCSE results tell us what we already know: if you get tutored and coached before an exam, you'll do better.


Are tutoring and coaching the only forms of community assistance? There is another one: impersonation. In other words, the parents hire a smart student from their community to take the exam in their child's place. This strategy is feasible only if the community has enough individuals who are (1) intelligent and (2) similar in age and appearance to the student in question. Such individuals are lacking in a small community, as are the middlemen who can refer an anxious parent to a suitable source of assistance.


How common is this strategy? Adebayo (2013) studied cheating behavior among Nigerian university students and British university students. He found that impersonation services were used or provided by 20% of the former and 1% of the latter. In general, cheating took non-collaborative forms among British students and collaborative forms among Nigerian students:


These include behaviours like writing somebody's coursework, colluding with others to communicate answers to one another, over marking one another's course work etc. This is quite different from plagiarism and non-collaborative cheating characteristic of the British sample reported by Newstead et al (1996). Reasons for these differences may be attributable to differences in population, differences in cultural ethnic, differences in emphasis placed on examination as part of educational assessment (Adebayo 2013, p. 146)


Adebayo (2013, p. 148) found high rates of collaborative cheating among Nigerian students:


Permitting own coursework to be copied - 72.6%

Copying another student's coursework with consent - 47.3%

Collaborative generous marking of coursework - 64.6%

Submitting joint work as an individual's - 49.3%

Doing another student's coursework for them - 77.3%

Collusion with another student to communicate answers - 83%


We live in a world that has low-trust and high-trust societies. In a high-trust society, like the UK, cheating is considered shameful and disreputable, regardless of whom you cheat. In a low-trust society, like Nigeria, cheating is wrong only when you do it to friends and relatives.


What happens when individuals from a low-trust society migrate to a high-trust one? If they come in sufficient numbers, their opportunities for collaborative cheating are greatly increased. Imagine you're supervising an exam in an English school, and you suspect an African student is filling in for another. He shows you his school card and another piece of ID. Both are correct. So what do you do now? Do you really want to make a fuss and risk being accused of racial profiling? No you don't.


Future research


The GCSE study by Demie (2013) leaves much to be desired. It does not provides the number of students who had to retake that exam (which must be a large number); nor does it provide a breakdown of the number of students taking it per year.


In any case, the GCSE is a poor substitute for an IQ test. Even if we exclude cheating, the results are distorted by legitimate activities like tutoring and coaching. The latter are more available to some students than to others. Consequently, GCSE results tell us nothing about differences in raw cognitive ability, either between individuals or between communities.


Chanda promises to write an article that will rule out cheating as an explanation for Nigerian success on the GCSE. Again, the issue isn't just cheating. It's any assistance that goes to some students and not to others. If you want to measure raw cognitive ability, you need a level playing field. In particular, you need a test that does not offer high achievers the lure of personal gain, which may push test-takers to do well by hook or by crook. In the UK, an African with good GCSE results has access to a wide range of good-paying jobs, in large part because of "diversity quotas" of one sort or another.


This motive comes out in interviews with the parents of African students:


● 'Without an education you cannot earn a decent salary, without qualifications you cannot get a good job. The best thing is to push your children as hard as you can.'

● 'Being a Black woman if you don't have education in this country, what job will you have to do, clean people's toilets?'  (Demie 2013, p. 13)


This subject should definitely be a research priority. We need IQ data on Nigerians, and not inadequate substitutes like GCSE scores. We also need data on alleles associated with educational attainment (i.e., polygenic scores). Furthermore, we need data on each of Nigeria's ethnic groups, particularly the Igbo. It's hard to fake intelligence in the real world, and the Igbo have a long history of doing better at business and other endeavors. Unfortunately, intelligent people are also better at cheating, so there is some confounding between real intelligence and the fake kind.




Adebayo, S.O. (2011). Common Cheating Behaviour among Nigerian University Students: A Case Study of University of Ado-Ekiti, Nigeria. World Journal of Education 1(1): 144-149.



Chisala, C. (2015). The IQ Gap Is No Longer a Black and White Issue. The Unz Review, June 25



Chisala, C. (2020). Nigerians, Jews and Scrabble: An Update on the IQ Debate. The Unz Review, February 27



Demie, F. (2013). Raising Achievement of Black African Pupils. Good Practice in Schools. London: Lambeth Research and Statistics Unit, Lambeth Council.



Frost, P. (2015). The Jews of West Africa. The Unz Review, July 4



Tuffiash, M., R.W. Roring, and K.A. Ericsson. (2007). Expert performance in SCRABBLE: Implications for the study of the structure and acquisition of complex skills. Journal of Experimental Psychology: Applied, 13(3), 124-134. https://doi.org/10.1037/1076-898X.13.3.124