 | Below are answers to frequently asked questions about the corresponding page User:MjolnirPants. They address concerns, questions, and misconceptions which have repeatedly arisen on the talk page. Please feel free to change this material in light of new discussion. |
Is there really a scientific consensus that there is no evidence for a genetic link between race and intelligence?
Yes, and for a number of reasons. Primarily:
- No evidence for such a connection has ever been published. A statement signed by 143 senior human population geneticists states categorically that genetics research in no way supports the view that "recent natural selection has led to worldwide differences in I.Q. test results". (See this for context.)
- As understanding of the human genome and the science of population genetics advances, it has become increasingly clear that race is not a biologically meaningful way to categorize human population groups. See for example this statement by the American Association of Physical Anthropologists.
- Even if we take ancestral population groups to be proxies for race, most subject-matter experts agree that cognitive differences between such such groups are unlikely to exist. A group of prominent geneticists explains why here.
- Extensive evidence has been published which indicates that observed differences in IQ test performance between racial groups are environmental in origin. A group of leading psychologists summarizes some of these findings here.
- Most researchers view the idea of a genetic connection between race and intelligence as scientifically obsolete. See e.g. this statement by the editorial board of Nature.
Isn't it true that different races have different average IQ test scores?
On average and in certain contexts, yes, though these differences have fluctuated and in many cases steadily decreased over time. Crucially, the existence of such average differences today does not mean what racialists have asserted that it means (i.e. that races can be ranked according to their genetic predisposition for intelligence). Most IQ test data comes from North America and Europe, where non-White individuals represent ethnic minorities and often carry systemic burdens which are known to affect test performance. Studies which purport to compare the IQ averages of various nations are considered methodologically dubious and extremely unreliable. Further, important discoveries in the past several decades, such as the Flynn effect and the steady narrowing of the gap between low-scoring and high-scoring groups, as well as the ways in which disparities such as access to prenatal care and early childhood education affect IQ, have led to an understanding that environmental factors are sufficient to account for observed between-group differences.
And isn't IQ a measure of intelligence?
Not exactly. IQ tests are designed to measure intelligence, but it is widely acknowledged that they measure only a very limited range of an individual's cognitive capacity. They do not measure mental adaptability or creativity, for example. You can read more about the limitations of IQ measurements here. These caveats need to be kept in mind when extrapolating from IQ measurements to statements about intelligence. But even if we were to take IQ to be a measure of intelligence, there would still be no good reason to assert a genetic link between race and intelligence (for all the reasons stated elsewhere in this FYI).
Isn't there research showing that there are genetic differences between races?
Yes and no. A geneticist could analyze a DNA sample and then in many cases make an accurate statement about that person's race, but no single gene or group of genes has ever been found that defines a person's race. Such variations make up a minute fraction of the total genome, less even than the amount of genetic material that varies from one individual to the next. It's also important to keep in mind that racial classifications are socially constructed, in the sense that how a person is classified racially depends on perceptions, racial definitions, and customs in their society and can often change when they travel to a different country or when social conventions change over time (see here for more details).
So how can different races look different, without having different genes?
They do have some different genes, but the genes that vary between any two given races will not necessarily vary between two other races. Race is defined phenotypically, not genotypically, which means it's defined by observable traits. When a geneticist looks at the genetic differences between two races, there are differences in the genes that regulate those traits, and that's it. So comparing Africans to Europeans will show differences in genes that regulate skin color, hair texture, nose and lip shape, and other observable traits. But the rest of the genetic code will be essentially the same. In fact, there is much less genetic material that regulates the traits used to define the races than there is that regulates traits that vary from person to person. In other words, if you compare the genomes of two individuals within the same race, the results will likely differ more from each other than a comparison of the average genomes of two races. If you've ever heard people saying that the races "are more alike than two random people" or words to that effect, this is what they were referring to.
Why do people insist that race is "biologically meaningless"?
Mostly because it is. As explained in the answer to the previous question, race isn't defined by genetics. Race is nothing but an arbitrary list of traits, because race is defined by observable features. The list isn't even consistent from one comparison to another. We distinguish between African and European people on the basis of skin color, but what about Middle Eastern, Asian, and Native American people? They all have more or less the same skin color. We distinguish African and Asian people from European people by the shape of some of their facial features, but what about Native American and Middle Eastern people? They have the same features as the European people, or close enough to engender confusion when skin color is not discernible. Australian Aborigines share numerous traits with African people and are frequently considered "Black" along with them, yet they are descended from Asian people and have been a distinct cultural and ethnic group for fifty thousand years. These standards of division are arbitrary and capricious; the one drop rule shows that visible differences were not even respected at the time they were still in use.
But IQ is at least somewhat heritable. Doesn't that mean that observed differences in IQ test performance between ancestral population groups must have a genetic component?
This is a common misconception, sometimes termed the "hereditarian fallacy".[1] In fact, most geneticists believe that the genes which determine intelligence are likely to be evenly distributed across existing ancestral population groups, with similar patterns of variation between families and individuals within these groups.[2] As geneticist and neuroscientist Kevin Mitchell explains:
Among the minority of geneticists who believe that cognitive differences between ancestral populations are likely to exist, the consensus is that such differences must be minuscule and, further, that we currently have no indication which groups are likely to be favored by cognitive advantages. Geneticist David Reich represents this view, stating his belief that while "very modest differences across human population in the genetic influences on behavior and cognition are to be expected [...] we do not yet have any idea about what the differences are".[4] Thus, geneticists roundly reject the idea that the heritability of IQ indicates that observed differences in IQ test performance between ancestral population groups have a genetic component.We need to get away from thinking about intelligence as if it were a trait like milk yield in a herd of cattle, controlled by a small, persistent and dedicated bunch of genetic variants that can be selectively bred into animals from one generation to the next. It is quite the opposite – thousands of variants affect intelligence, they are constantly changing, and they affect other traits. It is not impossible for natural selection to produce populations with differences in intelligence, but these factors make it highly unlikely.
To end up with systematic genetic differences in intelligence between large, ancient populations, the selective forces driving those differences would need to have been enormous. What’s more, those forces would have to have acted across entire continents, with wildly different environments, and have been persistent over tens of thousands of years of tremendous cultural change. Such a scenario is not just speculative – I would argue it is inherently and deeply implausible.
The bottom line is this. While genetic variation may help to explain why one person is more intelligent than another, there are unlikely to be stable and systematic genetic differences that make one population more intelligent than the next.[3]
What about all the psychometricians who claim there's a genetic link?
The short answer is: they're not geneticists. The longer answer is that there remains a well-documented problem of scientific racism, which has infiltrated psychometry. Psychometry is a field where people who advocate scientific racism can push racist ideas without being constantly contradicted by the very work they're doing. And when their data did contradict their racist views, many prominent advocates of scientific racism simply falsified their work or came up with creative ways to explain away the problems. See such figures as Cyril Burt, J. Phillipe Rushton, Richard Lynn, and Hans Eysenck, who are best known in the scientific community today for the poor methodological quality of their work, their strong advocacy for a genetic link between race and intelligence, and in some cases getting away with blatant fraud for many years.
Isn't it a conspiracy theory to claim that psychometricians do this?
No. It is a well-documented fact that there is an organized group of psychometricians pushing for mainstream acceptance of racist, unscientific claims. See this, this and this, as well as our article on scientific racism for more information.
What about the surveys of psychometricians that say that most believe that the difference in IQ between races is only partially due to environmental causes?
- These surveys are almost invariably conducted by advocates of scientific racism.
- Respondents to these surveys are also almost exclusively members of groups that promote scientific racism.
- These surveys tend to have very low participation rates, and often consist of fewer than 100 respondents.
- Many of the surveys suffer from methodological flaws, such as using leading questions. This leads to an increase in responses from those who agree, and a decrease from those who disagree.
- Generally speaking, the better the methodology of the survey, the lower agreement it shows with the claim of a genetic link between race and intelligence.
- Even the most poorly structured surveys, conducted among members of groups that are dominated by advocates for scientific racism, show much doubt and difference of opinion among respondents.
- In such surveys, the average percentage of the measured delta (about 15 points between the highest average racial score and the lowest average racial score) estimated to be explained by genetics is 1-5%; less than half the delta expected between two identical IQ tests taken by the same person on different days. In other words: statistically meaningless.
- The vast majority of respondents have absolutely no qualifications to speak on genetics.
What do other scientists have to say about the question of a genetic link between race and intelligence?
Surprisingly little, as to most scientists, this question is inherently pseudoscientific. It proposes an unexplained genetic mechanism where none has been observed, and there is no description of how it could possibly work. When they do weigh in on the subject, they are usually dismissive, considering the notion "unintelligible and wrong-headed," and comparing it to creationism, vaccine skepticism, and climate change denialism.
What is the evidence for a genetic link between race and intelligence?
Absolutely nothing. No such evidence has ever been presented in the scientific community. Much data has been claimed to be evidence by advocates of scientific racism, but this is universally rejected by geneticists. As has been mentioned already, there is not even any proposed mechanism by which such a link could exist, let alone any evidence for race having an impact on intelligence. This is why the question of such a genetic link is considered pseudoscience; it is assumed to exist only by advocates of scientific racism, and it is based on nothing but their own preconceived notions about race.
What is the current state of the science on a link between intelligence and race?
Please see the article itself for an outline of the scientific consensus.
What is the basis for Wikipedia's consensus on how to treat the material?
Wikipedia editors have considered this topic in detail and over an extended period. In short, mainstream science treats the claim that genetics explains the observable differences in IQ between races as a fringe theory, so we use our own guidelines on how to treat such material when editing our articles on the subject. Please refer to the following past discussions: