2500 words

Over three years ago I provided an argument with the ultimate conclusion that IQ tests should be banned. The gist of the argument is that if we believed the hereditarian hypothesis is true and we make policy ascription based on the hereditarian hypothesis and the results that were derived from IQ tests, then a policy could be enacted that would harm a group, and if the policy were enacted, then it would do harm to a group. Thus we should ban whatever led to the policy in question, and so if IQ tests led to the policy in question then IQ tests should be banned. In this article, I will strengthen each premise and then I will provide another argument for why IQ tests should be banned. Here’s the argument:

(P1) The Hereditarian Hypothesis is false
(P2) If the Hereditarian Hypothesis is false and we believed it to be true, then policy A could be enacted.
(P3) If Policy A is enacted, then it will do harm to group G.
(C1) If the Hereditarian Hypothesis is false and we believed it to be true and policy A is enacted, then it will do harm to group G (Hypothetical Syllogism, P2, P3).
(P4) If the Hereditarian Hypothesis is false and we believed it to be true and it would harm group G, then we should ban whatever led to policy A.
(P5) If Policy A is derived from IQ tests, then IQ tests must be banned.
(C2) Therefore, we should ban IQ tests (Modus Ponens, P4, P5).

Premise 1: The truth or falsity of this premise would divide people. On the one hand, there are proponents of the hereditarian hypothesis who believe that the hereditarian hypothesis is true, and so by banning their main “measurement tool”, then we would be censoring “the truth of human biodiversity.” But what entails “the hereditarian hypothesis”? The hereditarian hypothesis can also be called the generic theory of intelligence. It’s main claim is that the observed differences in IQ between groups and individuals are largely attributed to genetic factors. For example, Rushton and Jensen (2005) claim to take the middle ground in arguing that it’s 50/50 genes and environment that lead to the IQ phenotype. But Rushton and Jensen (2005: 279) claim that the 50/50 estimate of heritability is too low—80 percent G and 20 percent E is what we should assume:

A conundrum for theorists of all persuasions, however, is that there is too little evidence of any environmental effects. The hereditarian model of Black–White IQ differences proposed in Section 2 (50% genetic and 50% environmental), far from precluding environmental factors, requires they be found. Although evidence in Sections 3 to 11 provided strong support for the genetic component of the model, evidence from Section 12 was unable to identify the environmental component. On the basis of the present evidence, perhaps the genetic component must be given greater weight and the environmental component correspondingly reduced. In fact, Jensen’s (1998b, p. 443) latest statement of the hereditarian model, termed the default hypothesis, is that genetic and cultural factors carry the exact same weight in causing the mean Black–White difference in IQ as they do in causing individual differences in IQ, about 80% genetic–20% environmental by adulthood.

I have spent the better part of 3 years since publishing my original article to ban IQ tests arguing against the falsity of the hereditarian hypothesis on many grounds. The hereditarian hypothesis largely relies on heritability estimates derived from twin and adoption studies (and now shifting to neuroscience, like they have been since the 80s) and this is where the “laws of behavioral genetics” came from, but the “laws” fail. Important for the hereditarian position is the claim that science can study the mind. However, science is third-personal while mind is first-personal and subjective. Thus it follows that what is third-personal cannot study what is first-personal. Most important for the hereditarian position is the irreducibility of the mental—for if the claim is that the hereditarian hypothesis is true, then the mental would need to reduce to the physical. Humans have minds which means we have the ability for intentional states and propositional attitudes which implies that humans aren’t fully physical. If the argument there holds then science can’t study what’s immaterial, so there is a part of our constitution that can’t be studied by science. So at the end of the day, the hereditarian hypothesis is a physicalist position on the mind-body problem, but empirical evidence is irrelevant to conceptual arguments so the hereditarian position can’t help us understand the mind-body problem since it is an empirical position based on a supposed relationship between mind (“IQ”) and genes/brain/brain structure. Finally, the claim that there is a “general intelligence” is false; we don’t need a nonexistent, reified thing to explain the intercorrelations on IQ scores between individuals and groups. IQ tests are mere knowledge tests—and since knowledge is class-dependent, then different classes have different psychological and cultural tools, and so they would have different knowledge. Basically, IQ is an arbitrary notion especially due to the fact that tests can and have changed in the past for different social groups like men and women (Rosser, 1989), and two white South African groups (Hilliard, 2012) while Kidder and Rosner (2002) showed unconscious bias in the SAT favoring whites due to how the questions were selected. All of these considerations combine to show that the hereditarian hypothesis is false and that we should not accept conclusions from anyone who uses the hereditarian hypothesis as a guide.

Premise 2: But if we believed the hereditarian hypothesis to be true even when it’s false, then we may harm a group. For example, Jensen espoused some eugenic-type ideas in his infamous 1969 paper, stating:

“Is there a danger that current welfare policies, unaided by eugenic foresight, could lead to the genetic enslavement of a substantial segment of our population?” – Jensen, 1969: 95, How Much Can We Boost IQ and Scholastic Achievement?

“What the evidence on heritability tells us is that we can, in fact, estimate a person’s genetic standing on intelligence from his score on an IQ test.” – Jensen, 1970, Can We and Should We Study Race Difference?

“… the best thing the black community could do would be to limit the birth-rate among the least-able members, which of course is a eugenic proposal.” – A Conversation with Arthur Jensen, American Reinnasance, 1992

What Jensen wrote in his 1969 paper is similar to what Herrnstein and Murray (1994: 548) wrote:

We can imagine no recommendation for using the govemment to manipulate fertility that does not have dangers. But this highlights the problem: The United States already has policies that inadvertently social-engineer who has babies, and it is encouraging the wrong women. If the United States did as much to encourage high-IQ women to have babies as it now does to encourage low-lQ women, it would rightly be described as engaging in aggressive manipulation of fertility. The technically precise description of America’s fertility policy is that it subsidizes births among poor women, who are also disproportionately at the low end of the intelligence distribution. We urge generally that these policies, represented by the extensive network of cash and services for low-income women who have babies, be ended.

While these propositions don’t directly stem from hereditarian ideas, they are a direct consequence of such thinking. Like Shockley and Cattell’s beliefs and how their a priori racist ideas influenced the “science” they performed. So premises 2 and 3 presume a causal link between the hereditarian hypothesis, policy A and harm to group G. One specific example that immediately comes to mind is the sterilization or “morons”, “idiots”, and “imbeciles” in the 1900s even continuing up until the late 1970s. Perhaps the most famous case of this was the case of Carrie Buck, to which a judge famously stated, “Three generations of imbeciles are enough.” Premise 3 clearly has historical support.

Conclusion 1: So, since I’ve argued that P2 and P3 are true, then it follows that C1 is true as well. In the original article, I showed that blacks were disproportionately affected by IQ test rulings. Along with the fact that low IQ people were sterilized, this provides yet more support for the premises and the conclusion of this part of the argument.

Premise 4: I have already given the example above about the eugenics movement of the 1900s in America sterilizing thousands of people for having low IQs (this also occurred around the world). The Tuskegee Syphilis Experiment also lends credence to this premise. The US Public Health Service conducted a study from 1932 to 1972 on black Americans where they were observed with syphilis but they weren’t treated after penicillin became available. Segregation laws were based on the belief that the races were inherently different and shouldn’t mix. So in an attempt to prevent mixing, segregation was based on a false belief that blacks were inferior to whites. This is what Darby and Rury (2018) refer to as “the color of mind.”

The Color of Mind [the idea that”blacks were not equal to whites in intelligence, character, or conduct”] has served to rationalize racially exclusionary school practices and unequal educational opportunities, and the effects of these..have worked to sustain this racial ideology

Premise 5: Furthermore, government policies such as redlining and discriniminatory housing policies have led to segregation and inequalities/inequities in education (Rothstein, 2017). These example lend credence to the claim in P4 and P5—policies and practices derived from IQ or other standardized tests can be harmful if they contribute to existing inequalities and disparities. It is quite clear that IQ tests have been used to justify discriminatory polices in the past. Historical and recent considerations point to the fact that IQ tests can and have been used to perpetuate harm on individuals and groups (with the best example being the eugenics movement sterilizing low IQ people, sometimes without their knowledge). The other considerations that weren’t directly related to IQ tests like Tuskegee and Japanese Americans in WW2 show that beliefs that are false that are held to be true can and do lead to devestating consequences for groups of people. The arbitrariness of IQ can also be seen with the death penalty—there are literally life or death consequences riding on the results of a biased test. Moreover, IQ tests have been used to bar immigrants into America in the 1920s (Gould, 1981; Allen, 2006; Richardson, 2011).

Even if IQ tests haven’t been used to enact harmful policies in the past (they quite obviously have), potential future harm is enough. For example, IQ tests are biased in virtue of their item content. So if, say, an employer decides to use IQ tests to select job applicants, they will be necessarily biased by race and class. (Even though IQ tests don’t really have any predictive power for job performance, and whatever relationship between school performance is built in due to the relationship between the items on the tests.)

Thus, the conclusion of the argument that we should ban IQ tests follows. I have argued for the truth of premises 4 and 5 so it then follows that we should ban IQ tests. The argument is valid and I hold it to be sound. So we should ban IQ tests. Nevertheless, here is another argument that we should ban IQ tests:

P1: If IQ tests are not culturally biased and do not perpetuate social inequalities, then they should not be banned.
P2: IQ tests are culturally biased and perpetuate social inequalities.
P3: If IQ tests are culturally biased and perpetuate social inequalities, then IQ tests should be banned.
C: Therefore IQ tests should be banned.

Conclusion

I defended the premises in my original argument more in depth, giving more examples go each premise to justify and strengthen the overall argument. I then gave a new argument stating that since IQ tests at culturally biased, and perpetuate social inequalities then they should be banned. I will now close with a final argument that we should ban IQ tests (hypothetical syllogism):

P1: If IQ tests are biased and have a negative impact on people’s lives, then they should be banned.
P2: If IQ tests are banned, then they will no longer have a negative impact on people’s lives.
C: Therefore, if IQ tests are biased and have a negative impact on people’s lives, then IQ tests should be banned to eliminate  that harm.

All you need to do to see the goal of IQ-ists is to merely read what they write. IQ-ists like Jensen and Lynn have outright stated that we should in Jensen’s case limit the birthrate of the “least-able” while there is a danger that “current welfare policies unaided by eugenic foresight” could lead to a “genetic enslavement” of a substantial portion of the population. While in Lynn’s case, he was much more coy about it that we need to “phase out” such cultures (but he claimed it isn’t genocidal, though the term “phase out” of course tells you his real aims). Nevertheless, IQ-ists like Jensen, Lynn, Shockley, and Cattell have told us exactly what their views are. And their views are derived from, ultimately, heritability estimates derived from research with false assumptions. There is also the case that Pygmalion seems to be in the genes—the act of classifying one based on their polygenic score could have feedback effects based on how they view themselves and how society views them: “Through possible mechanisms of stigma and self-fulfilling prophecies, our results highlight the potential psychosocial harms of exposure to low-percentile polygenic scores for educational attainment” (Matthews et al, 2021).

I don’t even think it makes sense to claim that genes contribute to the ontogeny and differences in psychological traits between individuals. Genes only contribute to physical traits. Genes also don’t work how hereditarians need them to work. This is yet another reason why we should reject the hereditarian hypothesis and, along with it, stop using and banning IQ tests. The claim that genes contribute to the differences in psychological traits between people is not only false, but it has caused much harm since the argument has been mounted. Hereditarians have a ton of work to do on the conceptual front if they ever hope to have a sound basis for their beliefs. I’ve argued for a long time that it’s just not possible.

I don’t think we need a moratorium on these matters, such as behavioral genetics. I will be much more specific:

We need to outright cease and ban behavioral genetic research and IQ testing since they lead to avoidable harms. Since these things are based on flawed assumptions, and since these hardly have an evidentiary basis, the only recourse we should take on the matter is to outright ban them. The arguments given here definitively show that to be the case. If someone tells you who they are, then you listen to them. The main actors in the hereditarian sphere have told us who they are and what they stand for for decades, so we should listen to them and ban behavioral genetic and IQ tests. It’s only right to do so.

5000 words

Introduction

“General Intelligence” or g is championed as the hallmark “discovery” of psychology. First “discovered” by Charles Spearman in 1904, noting that schoolchildren who scored highly on one test scored highly on others and vice versa for lower-scoring children, he assumed that due to the correlation between tests, that there must be an underlying physiological basis to the correlation, which he posited to be some kind of “mental energy”, stating that the central nervous system (CNS) explained the correlation. He proclaimed that g really existed and that he had verified Galton’s claim of a unitary general ability (Richardson, 2017: 82-83). Psychometricians then claim, from these intercorrelations of scores, that what is hidden from us is then revealed, and that the correlations show that something exists and is driving the correlation in question. That’s the goal of psychometrics/psychology—to quantify and then measure psychological traits/mental abilities. However, I have argued at length that it is a conceptual impossibility—the goal of psychometrics is an impossibility since psychometrics isn’t measurement. Therefore, claims that IQ tests measure g is false.

First, I will discuss the reification of g and it’s relation to brain properties. I will argue that if g is a thing then it must have a biological basis, that is it must be a brain property. Reductionists like Jensen have said as much. But it’s due to the reification of g as a concrete, physical thing that has people hold such beliefs. Second, I will discuss Geary’s theory that g is identical with mitochondrial functioning. I will describe what mitochondria does, and what powers it, and then discuss the theory. I will have a negative view of it, due to the fact that he is attempting to co-opt real, actual functions of a bodily process and attempt to weave g theory into it. Third, I will discuss whether or not psychological traits are indeed quantifiable and measurable, and whether or not there is a definition psychometricians can use to ground their empirical investigations. I will argue negatively for all three. Fourth, I will discuss Herrnstein and Murray’s 6 claims in The Bell Curve about IQ and provide a response to each in turn. Fifth, I will discuss the real cause of score variation, which isn’t reduction to a so-called assumed existence of a biological process/mechanism, but which is due to affective factors and exposure to the specific type of knowledge items on the test. Lastly, I will conclude and give an argument for why g isn’t a thing and is therefore immeasurable.

On reifications and brain properties

Contrary to protestations from psychometricians, they in fact do reifiy correlations and then claim that there exists some unitary, general factor that pervades all mental tests. If reification is treating the abstract as something physical, and if psychometrics treat g as something physical, then they are reifying g based on mere intercorrelations between tests. I am aware that, try as they might, they do attempt to show that there is an underlying biology to g, but these claims are defeated by the myriad arguments I’ve raised against the reducibility of the mental to the physical. Another thing that Gould gets at is that psychometricians claim that they can rank people—this is where the psychometric assumption that because we can put a number to their reified thing, that there is something being measured.

Reification is “the propensity to convert an abstract concept (like intelligence) into a hard entity (like an amount of quantifiable brain stuff)” (Gould, 1996: 27). So g theorists treat g as a concrete, physical, thing, which then guides their empirical investigations. They basically posit that the mental has a material basis, and they claim that they can, by using correlations between different test batteries, we can elucidate the causal biological mechanisms/brain properties responsible for the correlation.

Spearman’s theory—and IQ—is a faculty theory (Nash, 1990). It is a theory in which it is claimed that the mind is separated into different faculties, where mental entities cause the intellectual performance. Such a theory needs to keep up the claim that a cognitive faculty is causally efficacious for information processing. But the claim that the mind is “separated” into different faculties fails, and it fails since the mind is a single sphere of consciousness, it is not a complicated arrangement of mental parts. Physicalists like Jensen and Spearman don’t even have a sound philosophical basis on which to ground their theories. Their psychology is inherently materialist/physicalist, but materialism/physicalism is false and so it follows that their claims do not hold any water. The fact of the matter is, Spearman saw what he wanted to see in his data (Schlinger, 2003).

I have already proven that since dualism is true, then the mental is irreducible to the physical and since psychometrics isn’t measurement, then what psychometricians claim to do just isn’t possible. I have further argued that science can’t study first-personal subjective states since science is third-personal and objective. The fact is the matter is, hereditarian psychologists are physicalist, but it is impossible for a purely physical thing to be able to think. Claims from psychometricians about their “mental tests” basically reduce to one singular claim: that g is a brain property. I have been saying this for years—if g exists, it has to be a brain property. But for it to be a brain property, one needs to provide defeaters for my arguments against the irreducibility of the mental and they also need to argue against the arguments that psychometrics isn’t measurement and that psychology isn’t quantifiable. They can assume all they want that it is quantifiable and that since they are giving tests, questionnaires, likert scales, and other kinds of “assessments” to people that they are really measuring something; but, ultimately, if they are actually measuring something, then that thing has to be physical.

Jensen (1999) made a suite of claims trying to argue for a physical basis for g,—to reduce g to biology—though, upon conceptual examination (which I have provided above) these claims outright fail:

g…[is] a biological [property], a property of the brain

The ultimate arbiter among various “theories of intelligence” must be the physical properties of the brain itself. The current frontier of g research is the investigation of the anatomical and physiological features of the brain that cause g.

…psychometric g has many physical correlates…[and it] is a biological phenomenon.

As can be seen, Jensen is quite obviously claiming that g is a biological brain property—and this is what I’ve been saying to IQ-ists for years: If g exists, then it MUST be a property of the brain. That is, it MUST have a physical basis. But for g proponents to show this is in fact reality, they need to attempt to discredit the arguments for dualism, that is, they need to show that the mental is reducible to the physical. Jensen is quite obviously saying that a form of mind-brain identity is true, and so my claim that it was inevitable for hereditarianism to become a form of mind-brain identity theory is quite obviously true. The fact of the matter is, Jensen’s beliefs are reliant upon an outmoded concept of the gene, and indeed even a biologically implausible heritability (Richardson, 1999; Burt and Simons, 2014, 2015).

But Jensen (1969) contradicted himself when it comes to g. On page 9, he writes that “We should not reify g as an entity, of course, since it is only a hypothetical construct intended to explain covariation am ong tests. It is a hypothetical source of variance (individual differences) in test scores.” But then 10 pages later on pages 19-20 he completely contradicts himself, writing that g is “a biological reality and not just a figment of social conventions.” That’s quite the contradiction: “Don’t reifiy X, but X is real.” Jensen then spent the rest of his career trying to reduce g to biology/the brain (brain properties), as we see above.

But we are now in the year 2023, and so of course there are new theoretical developments which attempt to show that Spearman’s hypothesized mental energy really does exist, and that it is the cause of variations in scores and of the positive manifold. This is now where we will turn.

g and mitochondrial functioning

In a series of papers, David Geary (2018, 2019, 2020, 2021) tries to argue that mitochondriaal functioning is the core component in g. At last, Spearman’s hypothetical construct has been found in the biology of our cells—or has it?

One of the main functions of mitochondria is to oxidative phosphorylation to produce adenosine triphosphate (ATP). All living cells use ATP as fuel, it acts as a signaling molecule, it is also involved in cellular differentiation and cell death (Khakh and Burnstock, 2009). The role of mitochondrial functioning in spurring disease states has been known for a while, such as with cardiovascular diseases such as cardiomyopathy (Murphy et al, 2016, Ramaccini at al, 2021).

So due to the positive manifold, where performance in one thing is correlated with a performance in another, Geary assumes—as Spearman and Jensen did before him—that there must be some underlying biological mechanism which then explains the correlation. Geary then uses established outcomes of irregular mitochondrial functioning to then argue that the mental energy that Spearman was looking for could be found in mitochondrial functioning. Basically, this mental energy is ATP. I don’t deny that mitochondriaal functioning plays a role in the acquisition of disease states, indeed this has been well known (eg, Gonzales et al, 2022). What I deny is Gary’s claim that mitochondrial functioning has identity with Spearman’s g.

His theory is, like all other hereditarian-type theories, merely correlative—just like g theory. He hasn’t shown any direct, causal, evidence of mitochondrial functioning in “intelligence” differences (nor for a given “chronological age). That as people age their bodies change which then has an effect on their functioning doesn’t mean that the powerhouse of the cell—ATP—is causing said individual differences and the intercorrelations between tests (Sternberg, 2020). Indeed, environmental pollutants affect mitochondrial functioning (Byun and Baccarelli, 2014; Lambertini and Byun, 2016). Indeed, most—if not all—of Geary’s hypotheses do not pass empirical investigation (Schubert and Hagemann, 2020). So while Geary’s theory is interesting and certainly novel, it fails in explaining what he set out to.

Quantifiable, measurable, definable, g?

The way that g is conceptualized is that there is a quantity of it—where one has “more of it” than other people, and this, then, explains how “intelligent” they are in comparison to others—so implicit in so-called psychometric theory is that whatever it is their tests are tests of, something is being quantified. But what does it mean to quantify something? Basically, what is quantification? Simply, it’s the act of giving a numerical value to a thing that is measured. Now we have come to an impasse—if it isn’t possible to measure what is immaterial, how can we quantify it? That’s the thing, we can’t. The g approach is inherently a biologically reductionist one. Biological reductionism is false. So the g approach is false.

Both Gottfredson (1998) and Plomin (1999) make similar claims to Jensen, where they talks about the “biology of g” and the “genetics of g“. Plomin (1999) claims that studies of twins show that g has a substantial heritability, while Gottfredson (1998) claims that heritability of IQ increases to up until adulthood where it “rises to 60 percent in adolescence and to 80 percent by late adulthood“, citing Bouchard’s MISTRA (Minnesota Study of Twins Reared Apart). (See Joseph 2022 for critique and for the claim that the heritability of IQ in that study is 0 percent.) They, being IQ-ists, of course assume a genetic component to this mystical g. However, there arguments are based on numerous false assumptions and studies with bad designs (and hidden results), and so they must be rejected.

If X is quantitative, then X is measurable. If X is measurable, then X has a physical basis. Psychological traits don’t have a physical basis. So psychological traits aren’t quantitative and therefore not measurable. Geary’s attempt at arguing for identity between g and mitochondrial functioning is an attempt at a specified measured object for g, though his theory just doesn’t hold. Stating truisms about a biological process and then attempting to liken the process with the construct g just doesn’t work; it’s just a post-hoc rationalization to attempt to liken g with an actual biological process.

Furthermore, if X is quantitative, then there is a specified measured object, object of measurement and measurement unit for X. But this is where things get rocky for g theorists and psychometricians. Psychometry is merely pseudo-measurement. Psychometricians cannot give a specified measured object, and if they can’t give a specified measured object they cannot give an object of measurement. They thusly also cannot construct a measurement unit. Therfore, “the necessary conditions for metrication do not exist” (Nash, 1990: 141). Even Haier (2014, 2018) admits that IQ test scores don’t have a unit that is like inches, liters, or grams. This is because those are ratio scales and IQ is ordinal. That is, there is no “0-point” for IQ, like there is for other actual, real measures like temperature. That’s the thing—if you have a thing to be measured, then you have a physical object and consequently a measument unit. But this is just not possible for psychometry. I then wonder why Haier doesn’t follow what he wrote to its logical conclusion—that the project of psychometrics is just not possible. Of course the concept of intelligence doesn’t have a referent, that is, it doesn’t name a property like height, weight, or temperature (Midgley, 2018:100-101). Even the most-cited definition of intelligence—Gottfredson’s—still fails, since she contradicts herself in her very definition.

Of course IQ “ranks” people by their performance—some people perform better on the test than others (which is an outcome of prior experience). So g theorists and IQ-ists assume that the IQ test is measuring some property that varies between groups which then leads to score differences on their psychometric tests. But as Roy Nash (1990: 134) wrote:

It is impossible to provide a satisfactory, that is non-circular, definition of the supposed ‘general cognitive ability’ IQ tests attempt to measure and without that definition IQ theory fails to meet the minimal conditions of measurement.

But Boeck and Kovas (2020) try to sidestep this issue with an extraordinary claim, “Perhaps we do not need a definition of intelligence to investigate intelligence.” How can we investigate something sans a definition of the object of investigation? How can we claim that a thing is measured if we have no definition, and no specified measured object, object of measurement and measurement unit, as IQ-ists seem to agree with? Again, IQ-ists don’t take these conclusions to their further logical conclusion—that we simply just cannot measure and quantify psychological traits.

Haier claims that PGS and “DNA profiles” may lead to “new definitions of intelligence” (however ridiculous a claim). He also, in 2009, had a negative outlook on identifying a “neuro g” since “g-scores derived from different test batteries do not necessarily have equivalent neuro-anatomical substrates, suggesting that identifying a “neuro-g” will be difficult” (Haier, 2009). But one more important reason exists, and it won’t just make it “difficult” to identify a neuro g, it makes it conceptually impossible. That is the fact that cognitive localizations are not possible, and that we reify a kind of average in brain activations when we look at brain scans using fMRI. The fact of the matter is, neuroreduction just isn’t possible, empirically (Uttal, 2001, 2014, 2012), nor is it possible conceptually.

Herrnstein and Murray’s 6 claims

Herrnstein and Murray (1994) make six claims about IQ (and also g):

(1) There is such a thing as a general factor of cognitive on which human beings differ.

Of course implicit in this claim is that it’s a brain property, and that people have this in different quantities. However, the discussion above puts this claim to bed since psychological traits aren’t quantitative. This, of course comes from the intercorrelations of test scores. But we will see that most of the source of variation isn’t even entirely cognitive and is largely affective and due to one’s life experiences (due to the nature of the item content).

(2) All standardized tests of academic aptitude or achievement measure this general factor to some degree, but IQ tests expressly designed for that purpose measure it most accurately.

Of course Herrnstein and Murray are married to the idea that these tests are measures of something, that since they give different numbers due to one’s performance, there must be an underlying biology behind the differences. But of course, psychometry isn’t true measurement.

(3) IQ scores match, to a first degree, whatever it is that people mean when they use the word intelligent or smart in ordinary language.

That’s because the tests are constructed to agree with prior assumptions on who is or is not “intelligent.” As Terman constructed his Stanford-Binet to agree with his own preconceived notions of who is or is not “intelligent”: “By developing  an exclusion-inclusion criteria that favored the  aforementioned groups, test developers created a norm “intelligent” (Gersh, 1987, p.166) population “to differentiate subjects of known superiority from subjects of known inferiority” (Terman, 1922, p. 656)” (Bazemoore-James, Shinaprayoon, and Martin 2017). Of course, since newer tests are “validated”(that is, correlated with) older, tests (Richardson, 1991, 2000, 2002, 2017; Howe, 1997), this assumption is still alive today.

(4) IQ scores are stable, although not perfectly so, over much of a person’s life.

IQ test scores are malleable, and this of course would be due to the experience one has in their lives which would then have them ready to take a test. Even so, if this claim were true, it wouldn’t speak to the “biology” of g.

(5) Properly administered IQ tests are not demonstrably biased against social, economic, ethnic, or racial groups.

This claim is outright false and can be known quite simply: the items on IQ tests derive from specific classes, mainly the white middle-class. Since this is true, it would then follow that people who are not exposed to the item content and test structures wouldn’t be as prepared as those who are. Thus, IQ tests are biased against different groups, and if they are biased against different groups it also follows that they are biased for certain groups, mainly white Americans. (See here for considerations on Asians.)

(6) Cognitive ability is substantially heritable, apparently no less than 40 percent and no more than 80 percent.

It’s nonsense to claim that one can apportion heritability into genetic and environmental causes, due to the interaction between the two. IQ-ists may claim that twin, family, and adoption studies show that IQ is X amount heritable so there must thusly be a genetic component to differences in test scores. But the issue with heritability has been noted for decades (see Charney, 2012, 2016, 2022; Joseph, 2014, Moore and Shenk, 2016, Richardson, 2017) so this claim also fails. There is also the fact that behavioral genetics doesn’t have any “laws.” It’s simply fallacious to believe that nature and nurture, genes and environment, contribute additively to the phenotype, and that their relative contributions to the phenotype can be apportioned. But hereditarians need to keep that facade up, since it’s the only way their ideas can have a chance at working.

What explains the intercorrelations?

We still need an explanation of the intercorrelations between test scores. I have exhaustively argued that the usual explanations from hereditarianism outright fail—g isn’t a biological reality and IQ tests aren’t a measure at all because psychometrics isn’t measurement. So what explains the intercorrelations? We know that IQ tests are comprised of different items, whether knowledge items or more “abstract” items like the Raven. Therefore, we need to look to the fact that people aren’t exposed to certain things, and so if one comes across something novel that they’ve never been exposed to, they thusly won’t know how to answer it and their score will then be affected due to their ignorance of the relationship between the question and answer on the test. But there are other things irrespective of the relationship between one’s social class and the knowledge they’re exposed to, but social class would still then have an effect on the outcome.

IQ is, merely, numerical surrogates for class affiliation (Richardson, 1999; 2002; 2022). The fact of the matter is, all human cognizing takes place in specific cultural contexts in which cultural and psychological tools are used. This means, quite simply, that culture-fair tests are impossible and, therefore, that such tests are necessarily biased against certain groups, and so they are biased for certain groups. Lev Vygotsky’s sociocultural theory of cognitive development and his concepts of psychological and cultural tools is apt here. This is wonderfully noted by Richardson (2002: 288):

IQ tests, the items of which are designed by members of a rather narrow social class, will tend to test for the acquisition of a rather particular set of cultural tools: in effect, to test, or screen, for individuals’ psychological proximity to that set per se, regardless of intellectual complexity or superiority as such.

Thinking is culturally embedded and contextually-specific (although irreducible to physical things), mediated by specific cultural tools (Richardson, 2002). This is because one is immersed in culture immediately from birth. But what is a cultural tool? Cultural tools include language (Weitzman, 2013) (it’s also a psychological tool), along with “different kinds of numbering and counting, writing schemes, mnemonic technical aids, algebraic symbol systems, art works, diagrams, maps, drawings, and all sorts of signs (John-Steiner & Mahn, 1996; Stetsenko, 1999)” (Robbins, 2005). Children are born into cultural environments, and also linguistically-mediated environments (Vasileva and Balyasnikova, 2019). But what are psychological tools? One psychological tool (which would also of course be cultural tools) would be words and symbols (Vallotton and Ayoub, 2012).

Vygotsky wrote: “In human behavior, we can observe a number of artificial means aimed at mastering one’s own psychological processes. These means can be conditionally called psychological tools or instruments… Psychological tools are artificial and intrinsically social, rather than natural and individual. They are aimed at controlling human behavior, no matter someone else’s or one’s own, just as technologies are aimed at controlling nature” (Vygotsky, 1982, vol. 1, p. 103, my translation). (Falikman, 2021).

The source of variation in IQ tests, after having argued that social class is a compound of the cultural tools one is exposed to. Furthermore, it has been shown that the language and numerical skills used on IQ tests are class-dependent (Brito, 2017). Thus, the compounded cultural tools of different classes and racial groups then coalesce to explain how and why they score the way they do. Richardson (2002: 287-288) writes

that the basic source of variation in IQ test scores is not entirely (or even mainly) cognitive, and what is cognitive is not general or unitary. It arises from a nexus of sociocognitive-affective factors determining individuals’ relative preparedness for the demands of the IQ test. These factors include (a) the extent to which people of different social classes and cultures have acquired a specific form of intelligence (or forms of knowledge and reasoning); (b) related variation in ‘academic orientation’ and ‘self-efficacy beliefs’; and (c) related variation in test anxiety, self-confidence, and so on, which affect performance in testing situations irrespective of actual ability.

Basically, what explains the intercorrelations of test scores—so-called g—are affective, non-cognitive factors (Richardson and Norgate, 2015). Being prepared for the tests, being exposed to the items on the tests (from which are drawn from the white middle-class) explains IQ score differences, not a mystical g that some have more of than others. That is, what explains IQ score variation is one’s “distance” from the middle-class—this follows due to the item content on the test. At the end of the day, IQ tests don’t measure the ability for complex cognition. (Richardson and Norgate, 2014). So one can see that differing acquisition of cultural tools by different cultures and classes would then explain how and why individuals of those groups then attain different knowledge. This, then, would license the claim that one’s IQ score is a mere outcome of their proximity to the certain cultural tools in use in the tests in question (Richardson, 2012).

The fact of the matter is, children do not enter school with the same degree of readiness (Richardson, 2022), and this is due to their social class and the types of things they are exposed to in virtue of their class membership (Richardson and Jones, 2019). Therefore, the explanation for these differences in scores need not be some kind of energy that people have in different quantities, it’s only the fact that from birth we are exposed to different cultures and therefore different cultural and psychological tools which then causes differences in the readiness of children for school. We don’t need to posit any supposed biological mechanism for that, when the answer is clear as day.

Conclusion

As can be seen from this discussion, it is clear that IQ-ist claims of g as a biological brain property fail. They fail because psychometrics isn’t measurement. They fail because psychometricians assume that what they are “measuring” (supposedly psychological traits) have a physical basis and have the necessary components for metrication. They fail because the proposed biology to back up g theory don’t work, and claiming identity between g and a biological process doesn’t mean that g has identity between that biological process. Merely describing facts about physiology and then attempting to liken it to g doesn’t work.

Psychologists try so very hard for psychology to be a respected science, even when what they are studying bares absolutely no relationship to the objects of scientific study. Their constructs are claimed to be natural kinds, but they are merely historically contingent. Due to the way these tests are constructed, is it any wonder why such score differences arise?

The so-called g factor is also an outcome of the way tests are constructed:

Subtests within a battery of intelligence tests are included n the basis of them showing a substantial correlation with the test as a whole, and tests which do not show such correlations are excluded. (Tyson, Jones, and Elcock, 2011: 67)

This is why there is a correlation between all subtests that comprise a test. Because it is an artificial creation of the test constructors, just like their normal curve. Of course if you pick and choose what you want in your battery or test, you can then coax it to get the results you want and then proclaim that what explains the correlations are some sort of unobserved, hidden variable that individuals have different quantities of. But the assumption that there is a quantity of course assumes that there is a physical basis to that thing. Physicalists like Jensen, Spearman, and then Haier of course presume that intelligence has a physical basis and is either driven by genes or can be reduced to neurophysiology. These claims don’t pass empirical and conceptual analysis. For these reasons and more, we should reject claims from hereditarian psychologists when they claim that they have discovered a genetic or neurophysiological underpinning to “intelligence.”

At the end of the day, the goal of psychometrics is clearly impossible. Try as they might, psychometricians will always fail. Their “science” will never be on the level of physics or chemistry, and that’s because they have no definition of intelligence, nor a specified measured object, object of measurement and measurement unit. They know this, and they attempt to construct arguments to argue their way out of the logical conclusions of those facts, but it just doesn’t work. “General intelligence” doesn’t exist. It’s a mere creation of psychologists and how they make their tests, so it’s basically just like the bell curve. Intelligence as an essence or quality is a myth; just because we have a noun “intelligence” doesn’t mean that there really exists a thing called “intelligence” (Schlinger, 2003). The fact is the matter is, intelligence is simply not an explanatory concept (Howe, 1997).

IQ-ist ideas have been subject to an all-out conceptual and empirical assault for decades. The model of the gene they use is false, (DNA sequences have no privileged causal role in development), heritability estimates can’t do what they need them to do, how the estimates are derived rest on highly environmentally-confounded studies, the so-called “laws” of behavioral genetics are anything but, they lack definitions and specified measured objects, objects of measurement and measurement units. It is quite simply clear that hereditarian ideas are not only empirically false, but they are conceptually false too. They don’t even have their concepts in order nor have they articulated exactly WHAT it is they are doing, and it clearly shows. The reification of what they claim to be measuring is paramount to that claim.

This is yet another arrow in the quiver of the anti-hereditarian—their supposed mental energy, their brain property, simply does not, nor can it, exist. And if it doesn’t exist, then they aren’t measuring what they think they’re measuring. If they’re not measuring what they think they’re measuring, then they’re showing relationships between score outcomes and something else, which would be social class membership along with everything else that is related with social class, like exposure to the test items, along with other affective variables.

Now here is the argument (hypothetical syllogism):

P1: If g doesn’t exist, then psychometricians are showing other sources of variation for differences in test scores.

P2: If psychometricians are showing other sources of variation for differences in test scores and we know that the items on the tests are class-dependent, then IQ score differences are mere surrogates for social class.

C: Therefore, if g doesn’t exist, then IQ score differences are mere surrogates for social class.