A post I have had in my “drafts” pile for some time… based on my readings of Stephen Jay Gould’s The Mismeasure of Man
For centuries, there has been a recurring, politically expedient project in Western thought: the attempt to measure the immeasurable complexities of human ability, distill them into a single, quantifiable number, and use that number to rank individuals and groups in a rigid hierarchy of worth. Today, this doctrine of biological determinism resurfaces, often cloaked in sophisticated statistics, but its philosophical heart remains rooted in an ancient and dangerous error.
The central concept sustaining this tradition is general intelligence, or g. Proponents of this theory argue that regardless of how intelligence manifests (be it verbal skill, spatial reasoning, or mathematical prowess), all mental activities share a common, underlying, and quantifiable intellectual substance. We must understand the fundamental fraud of g: it is not a biological discovery, but the statistical consequence of a profound philosophical mistake known as reification.
The Philosophical Sin of Reification
Reification is the propensity to convert an abstract concept, such as intelligence, into a hard entity or “thing” existing inside the brain. Since mental processes are recognized as important, we assign the label “intelligence” to this complex, multifaceted set of human capabilities. Once this abstract shorthand symbol is thus reified, it achieves the dubious status of a unitary thing located within the brain.
This process is inextricably linked to our desire for ranking. Once intelligence is conceived as a single entity, scientific procedure seems to dictate that a location and physical substrate be sought for it, enabling the quantification of intelligence as one number for each person. This single number then permits the linear ranking of people in a series of increasing worth. This entire framework—the belief in a measurable, genetically fixed, and unitary intelligence—has historically been used to find that disadvantaged groups are disadvantaged because they lack this “thing.” The is a long-help myth that has been thoroughly dispelled by generations of scholars.
Spearman and the Genesis of g as a Mathematical Illusion
The mathematical basis for the theory of g lies in the work of Charles Spearman, who essentially invented the technique of factor analysis. Factor analysis is a method designed to simplify large sets of correlated data by reducing dimensionality, recognizing ordered structure in fewer dimensions.
Spearman developed this technique specifically to study the basis of positive correlation observed among mental tests. When numerous tests are administered to a population, scores tend to correlate positively (people who do well on one test often do well on others). Factor analysis applies a mathematical transformation that yields a first principal component, which is mathematically robust because most correlation coefficients are positive.
Spearman took this abstract mathematical result, called the first principal component, and made the cardinal invalid inference that has plagued factor analysis ever since. He reified it as an entity and gave it an unambiguous causal interpretation, calling it g, or general intelligence. Spearman imagined he had identified a unitary quality underlying all cognitive mental activity—a quality that could be expressed as a single number and used to rank people. He felt compelled to argue that his g must measure some physical property of the brain, likening it to “mental energy” by analogy with physics.
However, the mere existence of this factor, even if strong, cannot justly lead to reification, because its presence is highly ambiguous in terms of causation. g can be interpreted in two contradictory ways that are both consistent with the correlation data: 1) it reflects an inherited level of mental acuity; or 2) it records environmental advantages and deficits (such as good schooling, access to books, and loving parents). By assuming the first interpretation without further evidence, Spearman established a theoretical justification for the unilinear scale that was later adopted by American hereditarians.
The Legacy of Fraud: Sir Cyril Burt
The most powerful proponent of the factor-analytic model of unitary intelligence was Sir Cyril Burt (1883-1971), who succeeded Spearman in Britain’s most influential psychology chair. Burt championed the definition of intelligence as i.g.c. (innate, general, cognitive) ability, insisting that this central, all-pervading factor “appears to be inherited, or at least inborn. Neither knowledge nor practice, neither interest nor industry, will avail to increase it”.
Burt’s career became infamous due to his documented fabrication of data. For instance, his foundational work on the IQ of identical twins raised apart—a crucial study for hereditarian claims—was proven fraudulent, including the suspicion that two of his key collaborators never existed.
While the conscious fakery was shocking, the sources emphasize that Burt’s real error was philosophical, not just statistical. His greater influence stemmed from his tenacious commitment to the error of reification. This dedication was so intense that when he considered the innateness of intelligence, his rational thinking evaporated before the hereditarian dogma that had granted him fame. He even descended into circular illogic, claiming that tests must measure innate intelligence because the testers constructed them to do so, thus begging the question itself.
The Path Binet Rejected
The American school of mental testing, led by Lewis M. Terman, aggressively promoted the idea of fixed, innate IQ, importing the scale originally devised by French psychologist Alfred Binet. Terman committed both core fallacies: he reified average test scores as a “thing” called general intelligence and assumed this “thing” was inherited.
This conversion was a complete perversion of Binet’s original intent. Binet had invented his scale for the limited, practical purpose of identifying French children who needed special educational help. Binet vigorously rejected the core tenets of the g theory. He insisted that intelligence was a wonderfully complex and multifarious property too complex to be captured by a single number capable of ranking children in a linear hierarchy. He cautioned against accepting the number “arbitrarily,” insisting that his score was only a rough, empirical guide and not a measure of anything innate or permanent.
Indeed, the mathematical necessity of a unitary g can be challenged completely. Psychologist L. L. Thurstone, writing from Chicago during the Great Depression, demonstrated that by rotating the factor axes derived from the correlation matrix to align with actual clusters of test performance (a method known as simple structure), the dominant general factor (g) could be made to disappear in favor of independent primary mental abilities (like verbal, math, or spatial ability). This demonstrated that g cannot have inherent reality, as it emerges only in one form of mathematical representation and attenuates or disappears in other mathematically equivalent forms.
The Enduring Misuse
The drive to reify intelligence as a single, fixed, innate quantity capable of linear ranking is a hoary old fallacy. Its resurgence, exemplified by the contemporary defense of g in works like The Bell Curve, correlates strongly with periods of political retrenchment and the destruction of social generosity.
The central arguments of these modern hereditarians fail because they rely on the same faulty premises established by Spearman and Burt: that intelligence can be depicted as a single number, that it is genetically based, and that it is effectively immutable. If these premises are false, the entire argument collapses.
The consequences of accepting this flawed concept are profound and human. We must not forget the effect these false arguments have on “lives diminished by these false arguments”. The greatest tragedy is the stunting of life and the deepest injustice is the denial of opportunity, imposed from without by this false system, but mistakenly identified as lying within the individual due to a belief in an immutable, numerical destiny called g.