Source: TW
Genetic basis for race
PART 18: Rebutting the Environmentalist Claim That ‘Race Is Purely a Social Construct’
In the last several threads, I’ve described the hereditarian explanation for racial differences in IQ. Let’s turn now to the rebuttal points made by those favoring an environmental hypothesis for the race IQ gaps. I’ll then rebut those rebuttals.
The main argument made by opponents of a hereditarian (genes-based) explanation for race IQ differences is a foundational one: They assert that because race is “purely a social construct” with “no biological basis,” these gaps are “meaningless.” This is partially correct –- race is a social construct, but it also has a biological basis. Both of these can simultaneously be true. Calling race purely a social construct, though, is scientifically indefensible.
David Reich, a leading scientist in population genetics (an area of science well positioned to investigate the biological basis of race), says: “Differences in genetic ancestry that happen to correlate to many of today’s racial constructs are real.”
I suspect Reich would probably agree more or less with the renowned evolutionary psychologist Steven Pinker that “every geneticist knows that the ‘race doesn’t exist’ dogma is a convenient PC 1/4-truth.”
Although it’s true that “genetic ancestry tests from companies like 23andMe function only because race exists and can be identified at a genetic level,” it’s also true that “racial categories have vague, poorly defined boundaries and can overlap.” There is no fixed or firmly-set number of racial groups, and “sometimes it will make sense to classify people into… continental races,” while “at other times it will be beneficial to classify [them] into smaller, more local groups at the regional level.”
Yes, there may perhaps be more precise and biologically meaningful genetic ancestry classifications that can be made for humans than continental race — for example, “Korean” is more precise than “Asian” — but the concept of “race” retains scientific value.
When IQ testing is conducted on smaller genetic clusters like “Korean,” do gaps in average group IQ disappear? Of course not — testing performed on these and other such groups shows the same type of gaps that testing of “races” does.
Editorial in journal Genome Biology: “[A] decade or more of population genetics research has documented genetic… differentiation among the races… Indeed, it is difficult to conceive of a definition of ‘biological’ that does not lead to racial differentiation.” It adds that the continental definition of race “need[s] some modification, because it is clear that migrations have blurred the strict continental boundaries… [ethnic groups] retain a great deal of genetic variation…” Jerry Coyne. professor eneritus at the University of Chicago, has written that the question “How many races exist?” is “pretty much unanswerable… one could delimit ‘Caucasians’ as a race, but within that group there are genetically different [subgroups],…” “Even if most human variation occurs within rather than between races, there are statistical differences between human groups that can, when combined, be used to delimit them… One could call Eurasians a race, or one could call Bedouins a race…” “… It all depends on how finely you want to divide things up,… and this is precisely what is expected if populations have evolutionary ancestry, which produces clusters of groups nested within each other.” Finally, Coyne writes: “The ‘sociological constructs’ thing is simply political correctness imposed on biological reality. In view of the morphological and genetic differences among human populations, how can such differences be ‘constructs’?” The 1000 Genomes Project identified five genetically-distinct races (“super populations”) containing between all of them 26 smaller “populations.” The races were African, European, East Asian, South Asian, and Admixed American. Another study concluded: “It is inaccurate to state that race is biologically meaningless… Recent research in genetics demonstrates that certain racial, and also ethnic categories have a biological basis in statistically discernible clusters of alleles.” Many recent and semi-recent population genetics and molecular biology studies support a biological basis for the traditional racial categories. You’ll see links to many of these studies at the end of this thread. Even when politically-motivated scientific declarations, such as this one by American Society of Human Genetics, are constructed and omit information to achieve a particular spin, look very carefully at the language because there’s only so far you can go with the spin. Of course “racial” divisions aren’t clear bright lines (no one is saying that), but even this political statement (look at its motivation) has to concede there are “clear observable correlations between variation in the human genome and how individuals identify by race.” The ASHG statement acknowledges that racial categories have a relationship to genetic differences. But it contends that there are no absolute boundaries between groups and that modern genetics allow for more finely-grained categories — hereditarians do not dispute this. Genetic ancestry and race can be fairly easily scientifically-identified by a variety of different methods –- DNA testing being the most accurate and well-known, already used on a consumer-basis by millions of people around the world. To demonstrate just how easy it is to identify races, there’s this astonishing fact: It only takes 100 random SNPs (the most common type of genetic variation among people) to classify individuals by race with 97% accuracy. A multivariate analysis of only 326 loci will increase accuracy, raising the correspondence between genetic clusters and race/ethnicity to 99.86%. Once you look at 1000s of loci, individuals from different populations are NEVER more closely related than individuals from the same population. (This being the case, how can anyone possibly defend on scientific grounds a position arguing that race is purely a social construct?) In one study involving analysis of 650,000 genetic variants there was perfect correspondence between self-reported ancestral origins and the global population groups established in the Human Genome Diversity Project. Other ways to identify or accurately predict the race of an individual include brain imaging techniques, machine learning and AI tools, anthropological forensics, and numerous physical differences (including bone density and a 1 SD difference in white blood cell count). In one recent study, researchers predicted individuals’ race using MRI brain scanning, and found that “genetic ancestry is encoded in the functional connectivity pattern of the brain at rest." Another study found that the 3-D geometry of cortical surface is “highly predictive of individuals’ genetic ancestry in West Africa, Europe, East Asia, and America, even though their genetic background has been shaped by multiple waves of migratory and admixture events.” Unsurprisingly, what scientists feel obliged by PC to say about the genetics of “race” to the general public differs from what they publish in their research, and in no area is this more true than in medical genetics research using the same GWAS/PRS models used in IQ research. An example is this article that bemoans the fact that GWAS/PRS medical research is being impeded because researchers are using mostly European-ancestry genetic data, which is “inaccurate” for other (especially African-ancestry) groups.
nature.com/articles/s4158… https://www.nature.com/articles/s41588-019-0379-x.epdf
If race were purely a social construct without a biological basis, then why would obtaining more genetic data from non-European groups be necessary in order to conduct “accurate” and “useful” medical research for non-European groups? The NY Times tells us that race is just a social construct with no biological reality when reporting on IQ gaps, but then informs us in its medical reporting that race and ethnicity markers are important to medical research, like they do here…
nytimes.com/2019/05/14/wel… The Intersection of Race and Blood (Published 2019) Blood can be racially or ethnically specific, so having more blood donors in certain groups can be crucial for saving the lives of patients who share their backgrounds. https://www.nytimes.com/2019/05/14/well/live/blood-type-race-racial.html … and here.
nytimes.com/2002/07/30/sci… Race Is Seen as Real Guide To Track Roots of Disease (Published 2002) Leading population geneticist Dr Neil Risch of Stanford University, in report in online journal Genome Biology prompted by 2001 editorial in New England Journal of Medicine, challenges widely held vie… https://www.nytimes.com/2002/07/30/science/race-is-seen-as-real-guide-to-track-roots-of-disease.html The importance of taking into account race and ethnicity in pharmacological research is a growing area of discussion and research. There is a sense that medical researchers are getting tired of having to tow the PC line about there being “only one race — the human race.” “Pharmacogenetic research in the past few decades has uncovered significant differences among racial and ethnic groups in the metabolism, clinical effectiveness, and side-effect profiles of many clinically important drugs. These differences must be taken into account.” And why are researchers at Cambridge University concerned that that bioweapons may be developed to attack specific racial and ethnic groups based on their DNA if race has no biological basis?
telegraph.co.uk/science/2019/0… World must prepare for biological weapons that target ethnic groups based on genetics, says Cambridge University Biological weapons could be built which target individuals in a specific ethnic group based on their DNA, a report by the University of Cambridge has warned. https://www.telegraph.co.uk/science/2019/08/12/world-must-prepare-biological-weapons-target-ethnic-groups-based/ Activist scientists sometimes try to dismiss studies that involve racial classifications because they often rely upon the individuals being studied being able to accurately self-identify their race, which they criticize as scientifically inaccurate. But they’re wrong. Racial self-identification has been found to be extremely accurate in studies — up to 99.86% accurate.
Very few people don’t know what race they are. Since the race of an individual can be identified, for example, in blood testing, brain imaging and scanning, and in analysis of a skeleton through forensic anthropological methods, among other ways, it’s preposterous to think race as lacking any biological basis. Ask yourself this: If the concept of “race” were to disappear, would that change the fact that those genetic clusters even acknowledged by blank slatists — let’s take the example again of “Pygmies” and “Korean” — have different average IQs? Answer: It wouldn’t. Ultimately the debate about group IQ gaps and genes doesn’t hinge upon the concept of “race” because there may be other more biologically meaningful and precise taxonomic classifications — for example, Pygmy and Korean, or Maori and Finn — than race. How did the idea that race has no biological meaning gain so much currency?
The answer couldn’t be simpler: The dominance (and occasional bullying) of the “anti-racist” left in academia. The idea that “race is purely a social construct” with no actual biological significance gained momentum, in particular, after a 1972 article (“The Apportionment of Human Diversity”) was published by the Marxist evolutionary biologist Richard Lewontin. The central argument of that article (now commonly referred to as “Lewontin’s Fallacy”) has been discredited by geneticist AWF Edwards and others, but, as is often the case in academia, the imperative to maintain political virtue trumped the weight of scientific evidence. But no political bullying or platitudinous virtue signaling can hide the plain and scientifically indisputable fact that taxonomic classifications of humans — whether by race or ethnicity or genetic/geographic (or some other genetic) cluster — vary in average IQ.
Brain difference evolution time
Source: TW
A VERY BASIC INTRODUCTION TO THE HEREDITARIAN POSITION ON RACE AND IQ.
PART 19: Rebutting the Environmentalist Claim That ‘50,000-150,000 Years Is Not Enough Time For Brain Differences To Evolve Between Groups’
Some scientists claim that there hasn’t been enough time for meaningful evolutionary changes to take place in the human brain in the 50,000 to 150,000 years since humans left Africa — changes that might have caused differences in IQ between geographically-separated groups.
Here, as in so many other areas of dispute in the race and IQ debate, the genomics revolution once again comes to the rescue, showing that there has been more than enough time in this interval of human history for natural selection to cause genes-influenced brain differences. David Reich:
“You will sometimes hear that any biological differences among populations are likely to be small, because humans have diverged too recently from common ancestors for substantial differences to have arisen under pressure of natural selection. This is not true.”
The belief that there hasn’t been enough time for differences to evolve in human brains (and therefore affect our innate behavior) was plausible when biologists assumed that evolution was a slow process, but the decoding of the human genome has undermined that assumption. Different human populations adapted to new environments and challenges as they spread out from Africa — obvious examples are genetic changes to allow for disease resistance, dairy consumption, and life in tropical, high-altitude, arctic, and other difficult climates.
“Selection pressures in response to regional conditions have influenced global human genomic diversity… None of these insights would be possible without global genome-wide population genetic data collected over the past 15 years.”
“Though we all share a human genome… genetic variation in that plan arises… as errors creep in each time DNA is copied… The accumulated genetic variation leads to variation in how our brains develop,” and ultimately to variation in cognition between groups (e.g., races).
Research using powerful new genomic tools is finding that over the past 1,000 to 15,000 years in Europe and parts of Asia “shifts in diet, lifestyle and environment introduced new [evolutionary] selection pressures…”
A 2019 study found direct evidence in the genome of evolutionary pressures taking place in European humans over the last 6,000 years by “comparing whole-genome data between Late Neolithic/Bronze Age individuals and modern Europeans,” including in “cognitive functions.”
Intelligence is a complex trait (i.e., “many genes each to small effect” influence it). A huge-sample (405,000 individuals) GWAS study of European, African, and East Asian populations in 2019 found that natural selection caused observed differences in the three complex traits studied, and that this selection had occurred on the trait since “the divergence of these populations” around 50,000 to 150,000 years ago, making it appear unlikely that other complex traits (such as intelligence) would have escaped the same evolutionary processes.
Researchers now realize that natural selection
“has been acting on us for the past 3,000 years, right up to the modern day… And it seems to be acting in surprising ways on complex traits encoded by multiple genes, such as those tied to intelligence…"
“There are mean differences in complex traits among global human populations… Our results support the hypothesis that natural selection has shaped the genetic differentiation of complex traits… among worldwide populations.”
A 2021 GWAS for 870 complex traits (including intelligence) “found that 88% of these traits underwent polygenic change in the past 2,000–3,000 years.”
The brain, of course, is a complex trait not immune from recent selection pressures. An interesting recent study found that a polygenic score for educational attainment has been decreasing over time in Iceland — evidence of very recent selection-driven brain changes. A 2021 study found that natural selection recently altered a number of traits including brain size. (You’ll recall that dozens of studies, including recent well-controlled ones involving thousands of individuals, have found a relationship between brain size and intelligence.)
New research is showing that polygenic selection over the past 2,000 years has influenced the physical structure of the brain, including the surface area of multiple cortical regions. There’s an explosion of research over the past few years shredding, study by study, the ideologically-driven talking point that meaningful changes in the human brain could not have occurred as population groups left Africa and spread across the globe.
Bottom line: Natural selection has operated on complex traits (which include intelligence) since humans left Africa 50,000 to 150,000 years ago, and some of this has occurred very recently, and probably has accelerated.
If in ONE human lifetime wild foxes were bred to become tame — a profound change in their brains — why is it so difficult to believe that human intelligence could have shifted 10% to 20% in one direction or another over THOUSANDS of human generations?
Analysis of the dog genome shows that it only took a few hundred years for large brain-based complex trait differences between dog breeds to take hold — differences that greatly exceed the relatively small change in just one human complex trait (intelligence).
“[S]elective breeding by humans has altered the gross organization of the brain in dogs… brain anatomy varies significantly in dogs, likely due to human-applied selection for behavior.”
Activist scientists usually won’t have a problem with an evolutionary claim made about any part of the human body other than the brain. So it’s not science at play; it’s politics. There’s are terms for this: “Evolution only below the head” and “cognitive creationism.”
“[Progressives] accept genetic explanations for things such as homosexuality,… addiction, and a variety of mental illnesses, but not for… group differences, and especially not when those… differences could explain… existing inequalities.”
If natural selection influenced the development of every system in the body (e.g., endocrine, immune, cardiovascular) why would our neurological systems (including the brain) have escaped this process? Why would the brain not been subject to adaptive demands? Even when evidence of huge and obvious genetically-based racial differences in traits is on display for billions of people to see –- as it is during the Olympic Games — the social pressure to not acknowledge it overwhelms reality.
If 50,000 to 150,000 years was enough time for natural selection pressures to cause such huge differences in human performance such as those on display in the sprint and long-distance running events, why is it difficult to believe that the brain would not have been affected? 96 out of the fastest 100 sprinters of all time are of western near-coastal sub-Saharan African descent, an area that contains less than 5% of the world’s population. All 71 of the fastest marathoners of all time are of East African descent (2% of world population).
Flynn
PART 20: Rebutting the Environmentalists Regarding the Flynn Effect, and James Flynn on Free Scientific Inquiry
A leading argument that has been used (more in the past than presently) against a hereditarian explanation for race IQ gaps relies upon the so-called “Flynn Effect,” named after the recently-deceased intelligence researcher James Flynn.
The Flynn Effect is the observed increase in IQ test scores that has taken place in many parts of the world in the 20th century. For example, an American receiving a score of 100 on an IQ test in 1990 would achieve a higher score if he took a test from 1950. The amount of the increase is generally believed to be around two to three points per decade.
In recent years, the Flynn Effect has started reversing in some developed countries, especially in western Europe — that is, tested intelligence is declining, on average. The precise causes of the Flynn Effect remain obscure, but there is general agreement that they are environmental, not genetic, in nature, and may relate to improvements in nutrition, education, opportunities for mental stimulation, and infectious disease control. Hereditarians (and many environmentalists) tend to believe that the reason the Flynn Effect is now reversing in developed countries is that environmental improvements impacting intelligence have reached a “natural ceiling.” The fact that the Flynn Effect provides evidence that IQ isn’t entirely in the genes — hardly a surprise to hereditarians — doesn’t, of course, demonstrate that IQ is mostly or wholly a product of the environment. But more to the point: The Flynn Effect has very little or nothing to say about race IQ gaps in the developed world because it shows the scores of ALL GROUPS INCREASING over time, and the US white-black IQ gap NOT MEANINGFULLY CHANGING with these increases. This suggests something relatively fixed in the gaps — something that cannot be changed by the environment/nurture.
Many, probably most, intelligence scientists believe that this something is “g” — that is, general intelligence itself. According to Richard Haier, “It is entirely possible that any actual increases in IQ scores are due to the non-g components of intelligence (this seems to be the case for the Flynn Effect).” As Arthur Jensen pointed out, the Flynn effect “is neutral for the hereditarian model because large environmental effects (up to 50% of the variance) are compatible with large genetic effects… [The finding] that the secular increase… …did not cluster with g and its biological correlates, however, may support the hereditarian model… [therefore] the hereditarian hypothesis is not disproven by the Flynn effect, whatever its cause(s).” A 2013 meta-analysis found: “The Flynn Effect is predominantly caused by environmental factors, and it is less plausible that these environmental factors play an important role in explaining group [e.g., race] differences in IQ. Flynn himself seemed to agree: “The magnitude of white/ black IQ differences… is correlated with the g loadings of the subtests; the magnitude of IQ gains over time on subtests is not usually so correlated; the causes of the two phenomena are not the same.” “[G]ains in IQ subtests (the Flynn effect) correlate negatively with their ‘g-loadedness’ (roughly how strong a proxy they are for the latent variable that explains most of the variance in IQ), while racial differences in IQ subtests show precisely the opposite trend.” That 2013 meta-analysis referred to above concluded: “It appears that the Flynn effect and group differences have different causes.” A statement signed by 52 leading intelligence researchers, published in the WSJ declared: “There is no persuasive evidence that the IQ bell curves for different racial-ethnic groups are converging” due to the Flynn Effect or any other reason. This graph illustrates the disconnect between the moving Flynn Effect and the relatively static amount of the black-white IQ gap. You can see that the IQ gap remained fairly steady for persons born in and after the 1960s. Interestingly, while Flynn (a socialist) was a hero of the left for years, he eventually came under fire for shifting the blame for the black-white IQ gap to black culture, which he saw as uninterested in providing intellectual stimulation to its children. It’s worth mentioning that Flynn also deserved credit for being one of the first prominent environmentalists to accept a role of genes in the race IQ gaps, via a “gene–culture correlation” theory that at least “accepts the paradox of large heritability estimates.” Most interestingly, Flynn was withering in his criticism of those who try to stop research into race and IQ:
“We no longer hear much from those who once proposed… that all races share so many genes in common that it would be absurd to look for genetic differences…” “Scholars at one of America’s most distinguished universities [admitted to me] they had never approved a research grant that might clarify whether black and white had equivalent genes for IQ…. The research should be done no matter what the outcome…” “Everyone knows that universities apply sanctions to [stop this research]… A stated intention of doing race/gene research on a vita will mean no job; doing that research may mean no tenure, no promotion, no research grants, or even a campaign for dismissal…” “The use of sanctions against those who do not confine their views on race and IQ… dictates limiting debate to the faculty… no wider discussion is allowed… no sign of dissent can be allowed to reach the public (no frank interviews given, no research pursued…” “I know of no alternative to the scientific method to maximize accumulation of truth about the physical world and the causes of human behavior. If scholars are to debate this issue, do we not want the best evidence possible–and this can only come from science…” “Scholars should stop playing games and let science do its job. Those of us who have turned their research into a contest rather than a diagnosis should be ashamed. I am not exempt from this censure…” “A final word to those who seek respectability by banning race/gene research: how much respectability would you get if your position were stated without equivocation? After all, those who refuse to investigate genetic equality between the races cannot label it true…” “[Y]et if you openly say it may not be true would you not reap the whirlwind? Honesty dictates this assertion: ‘I do not know if genetic equality is true and do not want to know.’ Say that, and see if your views are deemed innocent rather than pernicious.” I’ll talk about other rebuttal points made by those in the environmental camp tomorrow, including the argument that human intelligence cannot be reliably measured.