Why IQ Doesn’t Define Us: How a Number Came to Shape Education
1 February, 2026
Author Dr Will Zoppellini
What if a single number, designed to help schools spot who needed support the most, became one of the most misunderstood and damaging labels in education? Used to sort, limit, and exclude.
This is an examination of “IQ”. Not as a neat score on a page, but as an idea that infiltrated classrooms, shaped children’s futures, and blocked opportunity.
Picture a child sat down in a classroom where desks were not arranged alphabetically or by age, but by a number. The teacher had the scores in her hand. Without explanation, children were placed in an arc. Those with the highest results at one end, those with the lowest at the other. Responsibilities followed the pattern. Some children were asked to help, to lead, to demonstrate. Others were told to watch, to wait, to follow.
A few smiled, sitting a little taller in their chairs. Others stared at the floor, because they learned something that day that had nothing to do with reading or math. They learned that ability was a lottery, and their ticket had already been checked.
Long after the desks were moved again, the label lingered. It crept into how that child answered questions, how they compared themselves to others, how they explained their struggles at home. Years later, as an adult, they would still describe themselves with the same quiet certainty: “I was never very clever.” Without meaning to, they would pass that thought on to siblings, to colleagues, sometimes even to their own children.
Table of Contents
This is not a story invented for effect. Versions of this classroom existed across schooling systems within living memory. The furniture has changed, the language has softened, and the labels have been rebranded. But the belief beneath them has not entirely gone. Children are still examined early, sorted quickly, and spoken about as if their future had already been revealed.
In this post, we’ll confront the myths about IQ tests, where they came from, how they were meant to be used, and how they’ve been twisted into tools of exclusion and inequality.
So, make yourself comfortable, coffee in hand, and let’s confront how many of us were taught a story that simply wasn’t true.
The Origins: From Educational Support to Ability Label
When most people hear “IQ test,” they imagine a rigid measure of a human’s worth. But the real story begins in a classroom in Paris, as a practical, compassionate response to a problem in schooling1.
France, 1906, the introduction of near-universal primary education meant that, for the first time, classrooms included children who previously would have never attended school. Children developing at different rates, from different backgrounds, with different experiences. Many struggled to benefit from the standard curriculum, and teachers had little guidance on how to support them1,2.
The French government commissioned psychologist Alfred Binet, ‘to identify children who were not benefitting from the standard curriculum so that teachers could adjust instruction and provide them with support’. Along with Theodore Simon, they developed a series of tasks that reflected a child’s ability to handle everyday intellectual challenges. Things like remembering lists, identifying objects, or understanding instructions appropriate to age3,4. These tasks were assembled into different age levels so that a child’s performance could be compared to typical performance for their age group.
Crucially, Binet was explicit about the limits of this tool. A low score did not mean a child was “incapable of learning.” It meant that the child needed support and different teaching5. Binet did not conceive of intelligence as a single, fixed trait that could be captured in one score on one day and wrote passionately against this idea.
Some recent philosophers seem to have given their moral approval to these deplorable verdicts that affirm that the intelligence of an individual is a fixed quantity… We must protest and react against this brutal pessimism.
Binet wrote that children could achieve the same overall score through very different patterns of strengths and weaknesses, confirming his belief that intelligence consisted of multiple, partially independent faculties. This included attention, memory, imagination, judgement, and reasoning1. But when Binet’s ideas crossed the Atlantic, things changed.
In the United States, psychologist Lewis Terman translated and adapted the Binet–Simon scale, producing what became known as the Stanford–Binet Intelligence Scale6. Unlike Binet, Terman strongly believed that intelligence was innate, inherited, and largely fixed. Where Binet saw a snapshot of development, Terman saw a measure of destiny.
The Stanford-Binet Intelligence Scale introduced the familiar “Intelligence Quotient” or IQ: a ratio of mental age to chronological age, multiplied by 100. In roughly fifty minutes, children could be assigned a score that appeared precise, scientific, and final1,7.
What was meant to support differentiated instruction was effectively torn from its pedagogical roots and rebranded as a diagnosis of ability. Teachers, policymakers, and the public began treating IQ scores as definitive measures of potential, this misinterpretation propelled IQ beyond classrooms into hiring offices, military selection, and immigration policy. Understanding this origin story is essential because it reveals that many of the harms associated with IQ testing were not inevitable. They were choices.
The Separation of Intelligence Theory and Practice
The contrast between Binet’s nuanced vision and how IQ tests were used in practice is stark, and for me, heartbreaking. What happened next was not a sudden rupture, but a slow and consequential drift.
After World War I, the use of intelligence tests exploded. Psychologists developed Army Alpha and Beta tests to rapidly screen millions of draftees8. These group tests were designed for speed and efficiency, not deep understanding of individual potential, and were used, quite literally, to place people into roles and units9.
Soon, schools began administering group cognitive tests, not to help struggling learners, but to sort, categorise, track, and stream children based on scores. Low scorers were shunted into “remedial” or “slow learner” classes, with high scorers fast-tracked10. Scores were equated not with needs but with destiny.
Henry Goddard11, director of the Vineland Training School in New Jersey, used intelligence testing to classify students with developmental disabilities. Goddard believed that intelligence was largely innate and that identifying “mental deficiency” served society by allowing it to classify and manage populations more efficiently. This led to coining terms like “moron,” which quickly entered everyday language with dehumanizing force12.
Terman himself enthusiastically promoted the idea that IQ tests could identify society’s elite and its “less capable,” reinforcing educational inequities. In education, group intelligence tests flourished because they were cheap, quick to administer, and easy to score. Multiple-choice formats made large-scale testing possible, but they also narrowed what could be assessed. Intelligence testing became increasingly focused on classification rather than understanding1.
Once intelligence testing became a predictive technology, its purpose changed. Scores were no longer used primarily to ask, “What support does this child need?” but to answer, “What level should this child be allowed to reach?”13
The divorce between theory and practice became complete.
How IQ Testing Shaped Early Separation in Schooling
Once intelligence testing became embedded in schooling systems, its influence was rarely neutral.
IQ scores were often used to set ceilings especially for children from working-class backgrounds, children with special educational needs, and those whose language, culture, or behaviour did not align neatly with school expectations. These children were disproportionately labelled “low IQ” and tracked into restrictive settings14.
One of the most persistent ideas to emerge from early intelligence testing was that “you can tell the type of child early.” This belief became a justification for early separation within schooling systems1, particularly across western education contexts, where test data were used to decide who would cope with academic learning, who should be steered towards vocational routes, and who required containment rather than challenge.
A particularly stark example of early sorting in western schooling was the 11-plus in England and Wales, where intelligence theory was used to justify dividing children into separate educational futures at around age eleven12. Psychologists such as Cyril Burt helped bolster the belief that a general intelligence factor (g) could be measured and used to stream children into grammar schools (academic, well-resourced, linked to university routes) or secondary modern schools (often lower status and less resourced), with technical schools a small middle option. Although framed as “child-centred” placement, the system became rigid and binary. One performance could shape a child’s educational and occupational prospects, with limited chance to transfer. Despite the claims that children wouldn’t need to cram, schools often taught to the test, and pressure on children was intense. Outcomes were repeatedly affected by geography, teacher expectations, early streaming decisions, and socioeconomic resources. With middle-class children advantaged and late developers punished. In short, the 11-plus didn’t just measure children, it helped produce inequality by presenting selection as the objective12.
This consistent misuse wasn’t an accident, but a predictable effect when tests are treated as trustworthy indicators of innate ability, rather than context-based tools that must be interpreted carefully alongside professional judgement, classroom observation, and knowledge of each child’s environment.
IQ Testing, Race, and Educational Inequality
IQ testing didn’t just influence education it intersected with broader social and racial hierarchies in troubling ways. Throughout the twentieth century, IQ tests were disproportionately used to segregate black children1.
One of the clearest challenges to this practice came in the landmark lawsuit of Larry P. v. Riles15. In California, IQ tests were the primary basis for placing black children into classes labelled “educable mentally retarded.” The court ruled that this use was discriminatory and prohibited the practice. However, the ruling did not claim that IQ tests were invalid. Instead, it exposed how uncritical trust on scores, combined with biased interpretation and unequal systems, led to systematic exclusion.
This distinction is essential, because the harm wasn’t in the measurement itself, but in how numbers were treated as objective truths. Over time, IQ scores acquired an authority that masked the decisions embedded in testing: “what counts as intelligence”, “whose knowledge is valued”, “how norms are constructed”, and “where cut-off points are set”.
Beginning in the 1980s, scientist James Flynn showed that average IQ scores rose steadily across generations, particularly on tasks linked to abstract reasoning16. He documented that these gains occurred too rapidly to be explained by genetics and instead pointed to changes in access to education, health, better environment, and cultural demands16. Known as The Flynn Effect, this gives evidence that IQ scores are relative and not timeless measures of potential1.
It also highlights how intelligence testing, when embedded in unequal schooling systems, can function less as a tool for understanding learning and more as a mechanism for legitimising existing inequalities17. Social psychologist Jean-Claude Croizet argued that when intelligence is framed as an internal property of the child, inequality is explained as a “difference in ability” rather than difference in opportunity18.
What IQ Tests Actually Do: Key Takeaways
At their core, all psychological tests, including IQ tests, measure samples of behaviour. They assign numbers based on how individuals respond to specific questions or tasks.
IQ tests can reveal certain cognitive skills such as vocabulary, memory, pattern recognition, or problem solving compared to norms for people of the same age. These can provide useful information about how someone is currently performing in specific cognitive areas.
However, the tests’ content matters, as those relying heavily on language may reflect cultural or educational exposure as much as cognitive skill. Therefore, differences on those tasks probably tell us more about the environment than ability.
IQ tests were not designed to define intelligence or limit potential. They began as practical tools to identify learning support needs, not measures of fixed ability or human worth.
The power of IQ tests comes from how they are used, not what they measure. Problems arise when scores are treated as final verdicts rather than partial, contextual information.
IQ testing has a documented history of misuse in schooling. In unequal systems, test scores have been used to justify exclusion, particularly along racial and socioeconomic lines.
Responsible use requires humility and context. IQ scores should inform questions, not close conversations, and should never replace professional judgement, pedagogy, or opportunity.
Final Thoughts
A well-designed IQ test can do its job. It can offer a reasonably accurate snapshot of a child’s current cognitive functioning. But that is the limit of what it can do. An IQ score cannot tell us where those abilities came from, how they were shaped, or what that child might become. Those questions must always be considered and discussed.
Generations have lived with the consequences of misinterpreting IQ, carrying narrow labels into adulthood. Quietly shaping confidence, letting them define their opportunities. or worse, internalise judgments they were never meant to carry. As educators, parents, coaches, and humans, we must break the cycle of reducing children to numbers and instead nurture the rich, complex, ever-evolving potential inside every learner.
It is time to see intelligence not as a rank, but as a story in progress, one we are privileged to witness, support, and help to unfold.
Until next time, stay curious
Dr Will Zoppellini
References
- Sternberg, R.J. and Kaufman, S.B. eds. 2011.The Cambridge handbook of intelligence. Cambridge University Press.
- Esping, A. and Plucker, J.A. 2014. Alfred Binet and the children of Paris. InHandbook of intelligence: Evolutionary theory, historical perspective, and current concepts (pp. 153-161). New York, NY: Springer New York.
- Binet, A. and Simon, T. 1907. Le développement de l’intelligence chez les enfants.L’Année psychologique, 14(1), pp.1-94.
- Binet, A. and Simon, T. 1913.A method of measuring the development of the intelligence of young children. Chicago medical book Company.
- Dweck, C.S., 2009. Can we make our students smarter?.Education Canada, 49(4), p.56.
- Terman, L.M. and Merrill, M.A., 1960. Stanford-Binet intelligence scale: Manual for the third revision, form lM.
- Gillibrand, R. Lam, V. O’Donnell, V. 2016. Developmental Psychology. Pearson Education, Limited.
- Yerkes, R.M. and Yoakum, C.S. eds., 1920.Army mental tests. H. Holt.
- Gould, S.J. 1996.Mismeasure of man. WW Norton & company.
- Kevles, D.J. 1995.In the name of eugenics: Genetics and the uses of human heredity (No. 95). Harvard University Press.
- Goddard, H.H. 1920.Feeble-mindedness: Its causes and consequences. Macmillan.
- Murdoch, S., 2009.IQ: A smart history of a failed idea. Turner Publishing Company.
- Messick, S., 1995. Validity of psychological assessment: Validation of inferences from persons’ responses and performances as scientific inquiry into score meaning.American psychologist, 50(9), p.741.
- Neisser, U., Boodoo, G., Bouchard Jr, T.J., Boykin, A.W., Brody, N., Ceci, S.J., Halpern, D.F., Loehlin, J.C., Perloff, R., Sternberg, R.J. and Urbina, S. 1996. Intelligence: knowns and unknowns.American psychologist, 51(2), p.77.
- Riles, L.P.V. 495 F. Supp. 926 (ND Cal. 1979).Further Proceedings, 502.
- Flynn, J.R., 1987. Massive IQ gains in 14 nations: What IQ tests really measure.Psychological bulletin, 101(2), p.171.
- Neisser, U.E. 1998.The rising curve: Long-term gains in IQ and related measures. American Psychological Association.
- Croizet, J.C. 2012. The racism of intelligence: How mental testing practices have constituted an institutionalized form of group domination.