Did Chanda Chisala disprove hereditarianism? Not so fast. (Part One)

Back in September, Chanda Chisala wrote an article for the Unz Review in which he challenged the hereditarian hypothesis on the grounds that Black Africans do just as well as, and Nigerians better than, White British students in their General Certificate of Secondary Education (GCSE) examinations, which are taken at the age of 16. In addition, he noted that students from the Igbo and Yoruba Nigerian subgroups do almost as well as Asian Indians (who, academically, are the second highest-performing large ethnic group in the UK, after the Chinese). The claims regarding Nigeria and its subgroups will be dealt with in Part Two. Here, we will focus on the comparison between White British students and Black African students.

As was the case when Chisala previously wrote articles exploring this topic, many were too quick to dismiss the challenge to hereditarianism. Some attacked the GCSE examinations themselves, whilst others attacked the author.

The latter is obviously illogical, but what about the former? Should we trust the GCSE data? The answer is, resoundingly, a yes. For example, the celebrated 2007 paper by Ian Deary and colleagues looking at the association between the g factor and educational achievement found that there was a 0.72 correlation between g and students’ Best 8 GCSE scores, and a 0.69 correlation between g and GCSE total points score. The authors also note: “At age 16, obtaining five or more GCSEs at grades A–C is an important criterion… For those at the mean level of g at age 11, 58% achieved this; a standard deviation increase or decrease in g altered the values to 91% and 16%, respectively.”

Many noted that selection (both self-selection of immigrants and selection carried out by the UK Government) might be able to explain why the cohort of Black Africans in the UK perform reasonably well academically. Chisala dismissed this, claiming that selection would have to be so implausibly extreme to enable any immigrant group coming from a 70-IQ population to perform as well as a 100-IQ population.

I agree with Chisala: that does sound implausuble if sub-Saharan Africa has a genotypic IQ of 70. This is unlikely to be the case, however. First of all, Wicherts and colleagues have seriously challenged Richard Lynn’s claim that the 70 figure is the true phenotypic value, let alone the true genotypic value. They argue that a better estimate is 81, and accused Lynn of cherry-picking data. Lynn, in turn, returned the accusation. Rindermann (2012), who reviewed the competing claims and counter-claims, argued that the true value is likely to be around 75. This seems to me to be the most plausible of the three estimates.

Remember, though, that we are talking about the phenotypic IQ here. Estimates vary, but it’s plausible that, were developing countries fully developed, they would see an IQ boost of at least 10 points. In other words, even without taking into account considerations about self-selection and government selection, we might expect the average sub-Saharan African IQ in developed countries to be around 85 – similar to the average IQ of African-Americans. Admixture might give African-Americans a boost of a couple of points relative to sub-Saharan Africans, but some have speculatively argued that those who were taken as slaves were slightly less intelligent than average. So, 85 seems like a reasonable number to work with.

What do the latest test data tell us about the average IQ of Black Africans (and other ethnic groups) in the UK? An excellent dataset from the Cognitive Abilities Test (2009-2010), with sample sizes for each large ethnic group in the thousands (much higher than any of Lynn’s dated studies, for instance), is available to us. Every minority ethnic group, including the Chinese group, does significantly worse on the verbal component than on the quantitative and non-verbal component, suggesting some level of bias. For that reason, we’ll consider only the quantitative and non-verbal reasoning scores.

As per usual, the data show the Chinese group massively outperforming all other groups, with a non-verbal IQ of 112 and a quantitative reasoning score of almost 110. (Their verbal IQ scores are lower, at 100, part of which may be explained by bias and part of which may be explained by the observation that East Asians do significantly better on tests of abstract reasoning than on tests of verbal reasoning). Next come the Asian Indian and White British groups, who score around 100. Bangladeshis score around 96, and Pakistanis score around 95. Black African and Black Caribbean students score around 94.

An average IQ of 94 is significantly higher than our genotypic IQ of 85 for sub-Saharan Africa. Crucially, though, this can be explained by selection. A combination of higher IQ immigrants choosing to emigrate to the UK and the UK Government allowing only higher-skilled migrants to enter (as it does for those of non-EU origin) can easily explain why the average IQ of Black Africans in the UK is 9 points (0.6 standard deviations) higher than the mean genotypic IQ of sub-Saharan Africans.

At this point, Chisala might give two responses. Firstly, even if we accept that the genotypic IQ of sub-Saharan Africa is 85, wouldn’t the children (and grandchildren) or these immigrants regress to this racial mean of 85? The answer is no, because regression to the family mean is what really matters. “Regression to the racial mean” is useful to consider when there aren’t any more specific data on the population in question, but here we know that African immigrants are going to be a higher-IQ population than those they have left behind in their origin countries. Chisala betrays his ignorance of how genetics works by claiming that the IQs of the offspring of immigrants should necessarily regress to the mean IQ of their ancestral country.

Secondly, Chisala may reasonably ask how a 94-IQ population can be performing as well as a 100-IQ population academically, especially when Black Caribbean students (who also have an average IQ of 94) do substantially worse than both Black Africans and White British students.

The explanation that should immediately come to mind is differences in culture. Do some ethnic groups, on average, value education more than others? It’s obvious that the answer is yes, but such an explanation for why some groups may over or underperform academically relative to their measured IQ would be immediately ruled out if studies have found that the ‘shared environment’ does not explain much or any of the variance in academic achievement.

In actual fact, courtesy of Robert Plomin and colleagues at King’s College London, we know that it does. This 2013 paper found that the shared environment explains 30-35% of the variance in GCSE results, depending on the specific measure being used. Genetic differences account for around 60% of the variance, in turn. Still, it demonstrates that a substantial proportion of the variance in GCSE results can be explained by the shared environment.

Would we expect differences in the shared environment to explain why Black Africans do better than Black Caribbeans? Likely, yes. A substantial portion of Black Caribbean immigrants arrived in the UK in the late 1940s, 1950s and early 1960s. Black Africans, by contrast, arrived much more recently and as such are more likely to instil values such as discipline and hard work into their children.

Why, though, do Black Africans do about as well as White British students? It is more difficult to imagine that Black Africans in the UK have a culture so conducive to educational success that a 6-point IQ gap can be overcome. However, a closer look at the GCSE data provides us with a more nuanced picture of where exactly Black Africans are comparable to White British students. In turn, this provides us with a solution to the problem.

Chisala cites a study by the Oxford academic Steve Strand demonstrating that Black Africans do almost as well as White British students when it comes to their ‘Best 8’ GCSE results: the mean score of Black Africans in the study is 346.0, and for White British students it is 346.8 (as a comparison, the Chinese and Indian groups both scored above 380.0). When it comes to attaining 5 A*-C grades (including in English and Mathematics) at GCSE, a key benchmark that schools aim to reach, Black African students do slightly better than White British students: 62.1% attain this as compared to 61.9% of White British students.

Official UK Government statistics provide us with much the same picture: in 2015/16, the last year for which comparable data are available (due to reforms to the GCSEs), an equal percentage (63%) of Black African and White British students achieved 5 A*-C grades (including English and Maths) at GCSE. Yet, only 34% of White British students entitled to free school meals (a marker of poverty and deprivation) achieved this standard, compared to 67% of White British students not entitled to free school meals.

By contrast, Black African pupils entitled to free school meals did much, much better than their White British counterparts, with 53% achieving the standard, while those not entitled to free school meals actually did worse than their White British counterparts, with 66% achieving the standard. It can be calculated, from the raw data in the official statistics, that if White British students on free school meals performed as well as their Black African counterparts, the White British average would increase from 63% to more than 65%.

This huge gulf between the attainment of White British children in poverty and those who aren’t suggests that Black Africans don’t just have a culture more conducive to education, but that among White British communities, as you move further down the ladder of socioeconomic status, a toxic culture that actively undermines academic success begins to emerge. This is why there has been much more focus, recently, on improving the chances of White working-class students, particularly boys. As the Sutton Trust notes, White working-class boys are the worst performing group of individuals in the UK, followed by White working-class girls.

The distinction between those on free school meals and those not on free school meals is also likely to be a somewhat arbitrary one: this cultural malaise, documented well in the work of Theodore Dalrymple, likely affects much of White British society to some extent, with the worst effects at the bottom of the socioeconomic status distribution. In other words, all White British pupils, to a greater or lesser extent, would perform better academically were it not for environmental and cultural disadvantage.

The takeaway point from all of this is that Black African pupils are mainly outperforming White British pupils at the lower end of the ability spectrum: they are attaining ‘C’ grades, for instance, at much higher rates than White British pupils. This also increases their mean score, as expressed by their ‘Best 8’ score.

However, the evidence suggests that White British students do significantly better than Black African students when it comes to getting the top grades at GCSE. These pupils, who will disproportionately come from affluent backgrounds, are suffering the least from the anti-intellectual culture that seems to be afflicting White British society.

The Daily Mail has reported on one of the only studies to look at the performance of different ethnic groups when it comes to getting the top grades, which found that 55% of Chinese and 31% of Indian pupils achieved at least an A in GCSE Maths, compared with 16% of White British pupils, 14% of Black African pupils, 13% of Pakistani pupils and 8% of Black Caribbean pupils. In GCSE English, 29% of Chinese and 21% of Indian pupils achieved at least an A, compared to 15% of White British, 11% of Black African, 9% of Pakistani and 8% of Black Caribbean pupils.


To summarise, Black African students appear to have an average IQ of 94, which is entirely consistent with a genotypic IQ for sub-Saharan Africa of around 85. And although Black African students perform just as well as White British students (with an average IQ of 100) at GCSE level, this can be explained by environmental advantages in the Black African community and environmental disadvantages in the White British community (particularly in impoverished and deprived areas)

One final point: it is not hypocritical of hereditarians to invoke culture and environment. Most of the debate surrounding this usually focuses on SAT scores in the United States, which were, before recent changes, essentially IQ tests. We know from twin and adoptive studies that the shared environment explains very little of the variance in IQ. By contrast, the evidence suggests that it explains around a third of the variance in the central measure in question in this article, namely GCSE scores.

In the next post, I’ll be looking at Chisala’s claims regarding the performance of Nigerians in the UK, particularly the Igbo and Yoruba groups.


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