Alfred Binet and the History of IQ Testing

Table of ContentsView AllTable of ContentsHistoryFirst IQ TestStanford-Binet ScaleArmy Alpha and Beta TestsWechsler ScalesControversiesUsesA Word From Verywell

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Table of Contents

History

First IQ Test

Stanford-Binet Scale

Army Alpha and Beta Tests

Wechsler Scales

Controversies

Uses

A Word From Verywell

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Interest inintelligencedates back to more than a century ago.But it wasn’t until psychologist Alfred Binet was asked to identify which students needed educational assistance that the first intelligence quotient (IQ) test was born.

Although it has its limitations, Binet’s IQ test is well-known around the world as a way to assess and compare intelligence. It also set the stage for the development of several of the IQ tests that are still in use today.

This article discusses the history of intelligence tests, including Alfred Binet’s lasting contributions. It also explores modern variations of the test and controversies about the assessment of intelligence.

Thinkers Who Influenced Alfred Binet

Sensorimotor tasks are tasks or exercises that involve the brain receiving a message, then producing a response. An example would be driving a car and recognizing that the vehicle in front of you is slowing (the receipt of a message), causing you to hit your brakes to slow down as well (a produced response).

Galton also liked to usestatisticsto explain the data he collected, even though this information didn’t always verify his beliefs. For example, although he originally thought that head shape and size were correlated with intelligence, the data did not support this notion.

Galton himself was thought to be of higher intelligence, even as a child, with some suggesting that his IQ was “not far from 200” when he was under 8 years of age.According toIQ score ratings, this would have put him in the “profoundly gifted” category for intelligence.

Other psychologists of that time had their own ideas, such asJames McKeen Cattellwho proposed that simple mental tests could be used to measure intelligence.Yet, it wouldn’t be until a few years later that the first IQ test was born.

Alfred Binet and the First IQ Test

Alfred Binet was a French psychologist who played an important role in the development ofexperimental psychology. Although he originally pursued a career in law, Binet become increasingly interested in Galton’s attempts to measure mental processes—so much so that he abandoned his law career and set out to do the same.

At the time, the French government had laws requiring that all children attend school. So, it was important to find a way to identify the kids who would need extra help. In 1904, as part of this effort, the French government asked Binet to help decide which students were most likely to experience difficulty in school.

Binet and his colleague, Theodore Simon, began developing questions that focused on areas not explicitly taught in the classroom, such asattention,memory, andproblem-solving skills. They then worked to determine which questions best predicted academic success.

Binet and Simon ultimately came up with a test that included 30 questions, such as asking about the difference between “boredom” and “weariness,” or asking the test-taker to follow a moving object with just one eye.This became known as the Binet-Simon Scale and was the first recognized IQ test.

Binet quickly realized that some children were able to answer more advanced questions. Based on this observation, he suggested the concept of mental age, which is a measure of intelligence based on the average abilities of children within a certain age group.

At What Age Do Your Mental Powers Peak?

Limitations of the Binet-Simon IQ Test

This Binet-Simon Intelligence Scale (also sometimes called theSimon-Binet Scale) became the basis for the intelligence tests still in use today. Though, this scale had many limitations.

For example, Binet did not believe that his psychometric instruments could be used to measure a single, permanent, and inborn level of intelligence. Instead, he suggested that intelligence is far too broad a concept to quantify with one number.

The Binet-Simon test didn’t necessarily account for this complexity, providing an incomplete measure of intelligence. Some psychologists set out to make the modifications needed to supply a more complete picture, which led to the creation of newer, more comprehensive IQ tests.

Stanford-Binet Intelligence Scale

Stanford University psychologistLewis Termanis one professional who took Binet’s original test and standardized it using a sample of American participants. Initially, this was known as the Revised Stanford-Binet Scale. Today, Lewis Terman’s widely used American revision of Binet’s original intelligence test is known more commonly as the Stanford-Binet Intelligence Scale.

The Stanford-Binet test, which was first published in 1916, was adapted from the original test in that French terms and ideas were translated into English. It also included new terms, using two scales of measurement versus one to provide a more accurate score.

The Stanford-Binet intelligence test provided a single number, known as the intelligence quotient (IQ), to represent an individual’s score on the test. It remains a popular assessment tool today, despite going through a number of revisions over the years since its inception.

For example, a child with a mental age of 12 and a chronological age of 10 would have an IQ of 120: (12÷10) x 100 = 120.

At the outset of World War I, U.S. Army officials were faced with the task of screening and classifying an enormous number of recruits. In 1917, as chair of the Committee on the Psychological Examination of Recruits, psychologistRobert Yerkesdeveloped two IQ tests known as the Army Alpha and Beta tests.

The Army Alpha was designed as a written test, while the Army Beta was made up of pictures for recruits who were unable to read or didn’t speak English. The tests were administered to over 2 million soldiers.

The goal of the Alpha and Beta tests was to help the Army determine which men were suited for specific positions and leadership roles. After the war, the tests remained in use in a wide variety of situations outside of the military.

For example,IQ testswere used to screen new immigrants as they entered the United States. As a result of these tests, harmful and inaccurate generalizations were made about entire populations, leading Congress to enact discriminatory immigration restrictions for groups deemed to have a “genetically inferior” IQ.

Wechsler Intelligence Scales

Much like Alfred Binet, American psychologist David Wechsler believed that intelligence involved different mental abilities. But he wasn’t happy with the limitations of the Stanford-Binet so, in 1955, he published his new intelligence test known as theWechsler Adult Intelligence Scale(WAIS).

Wechsler developed two different tests specifically for use with children: the Wechsler Intelligence Scale for Children (WISC) and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). The adult version of the test has been revised since its original publication and is now known as the WAIS-IV.

WAIS-IV

This scoring method has become the standard in intelligence testing and is also used in the modern revision of the Stanford-Binet test. The WAIS-IV contains 10 subtests, along with five supplemental tests, and provides scores in four major areas of intelligence:

The WAIS-IV also provides two broad scores that can be used as a summary of overall intelligence. The Full-Scale IQ score combines performance on all four index scores while the General Ability Index is based on six subtest scores.

Debates Surrounding IQ Testing

There are also questions as to whether IQ tests are reliable.Reliabilityexists when the same test results are repeated over time. One pilot study involving the Wechsler Abbreviated Scale of Intelligence - Second Edition (WASI-II) found good reliability in some testing conditions and poor reliability in others.

Some of the controversies surrounding IQ tests revolve around the notion that they are inherently biased against certain ethnic groups, namely Black and Hispanic Americans.This apparent bias then can result in discrimination and disadvantages for these groups.

IQ Test Uses

At the same time, others believe that IQ tests offer some value, particularly in certain situations. A few of the ways intelligence tests are used today include:

Alfred Binet developed the world’s first official IQ test. His original test has played an important role in how intelligence is measured, as well as the future development of additional tests that are still in use today. While IQ testing remains a divisive topic, it continues to be widely used for a variety of purposes including for the purpose Binet originally designed his test—to help identify children who may need additional educational assistance.

18 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.De Boeck P, Gore LR, Gonzalez T, San Martin E.An alternative view on the measurement of intelligence and its history.Cambr Handbook Intellig. 2020:47-74. doi:10.1017/9781108770422.005Jastrzebski J, Kroczek B, Chuderski A.Galton and Spearman revisited: Can single general discrimination ability drive performance on diverse sensorimotor tasks and explain intelligence?.J Experiment Psychol. 2021;150(7):1279-1302. doi:10.1037/xge0001005Challis D.Skull triangles: Flinders Petric race theory and biometrics.Bull Hist Archaeol. 2016;26(1):p.Art.5. doi:10.5334/bha-556Terman L.The intelligence quotient of Francis Galton in childhood.Am J Psychol. 1917;28(2):209-215.Britannica.Alfred Binet: French psychologist.University of Washington.Alfred Binet’s IQ test, 1905.Becker K.History of the Stanford-Binet intelligence scales: Content and psychometrics. Stanford-Binet Intelligence Scales, Fifth Edition Assessment Service Bulletin No. 1.Greenwood J.Psychologists go to war.Behavioral Scientist.Allen G.Intelligence tests and immigration to the United States, 1900-1940.Wiley Online Library. 2006. doi:10.1002/9780470015902.a0005612American Psychological Association.IQ.Rindermann H, Becker D, Coyle T.Survey of expert opinion on intelligence: Intelligence research, experts' background, controversial issues, and the media.Intelligence. 2020;78:101406. doi:10.1016/j.intell.2019.101406Worhach J, Boduch M, Zhang B, Maski K.Remote assessment of pediatric patients with daytime sleepiness and healthy controls: A pilot study of feasibility and reliability.Child Neurol Open. 2021;8. doi:10.1177/2329048X211048064Reynolds C, Altmann R, Allen D.The problem of bias in psychological assessment.Mastering Modern Psychol Test. 2021;1621:573-613. doi:10.1007/978-3-030-59455-8_15Spielman R, Dumper K, Jenkins W, Lacombe A, Lovett M, Perlmutter M.40 measures of intelligence. Psychology - H5P Edition.van Ool J, Hurks P, Snoeijen-Schouwenaars F, et al.Accuracy of WISC-III and WAIS-IV short forms in patients with neurological disorders.Development Neurorehabil. 2018;21(2):101-107. doi:10.1080/17518423.2016.1277799Kahalley LS, Ris MD, Grosshans DR, et al.Comparing intelligence quotient change after treatment with proton versus photon radiation therapy for pediatric brain tumors.J Clin Oncol. 2016;34(10):1043-1049. doi:10.1200/JCO.2015.62.1383Holzinger A, Kickmeier-Rust M, Müller H.KANDINSKY patterns as IQ-test for machine learning.Machine Learn Knowl Extract. 2019;11713:1-14. doi:10.1007/978-3-030-29726-8_1Graham S, Depp C, Lee E, et al.Artificial intelligence for mental health and mental illnesses: An overview.Curr Psychiat Rep. 2019;21:116. doi:10.1007/s11920-019-1094-0Additional ReadingAntonson AE.Stanford-Binet Intelligence Scale.Encycloped Cross-Cultur School Psychol. 2015. doi:10.1007/978-0-387-7199-9_400Coalson DL, Raiford SE, Saklofske DH, Weiss LG.WAIS-IV: Advances in the assessment of intelligence.WAIS-IV Clin Use Interpret. 2010:3-23. doi:10.1016/B978-0-12-375035-8.10001-1Fancher RE, Rutherford A.Pioneers of Psychology(5th ed.).

18 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.De Boeck P, Gore LR, Gonzalez T, San Martin E.An alternative view on the measurement of intelligence and its history.Cambr Handbook Intellig. 2020:47-74. doi:10.1017/9781108770422.005Jastrzebski J, Kroczek B, Chuderski A.Galton and Spearman revisited: Can single general discrimination ability drive performance on diverse sensorimotor tasks and explain intelligence?.J Experiment Psychol. 2021;150(7):1279-1302. doi:10.1037/xge0001005Challis D.Skull triangles: Flinders Petric race theory and biometrics.Bull Hist Archaeol. 2016;26(1):p.Art.5. doi:10.5334/bha-556Terman L.The intelligence quotient of Francis Galton in childhood.Am J Psychol. 1917;28(2):209-215.Britannica.Alfred Binet: French psychologist.University of Washington.Alfred Binet’s IQ test, 1905.Becker K.History of the Stanford-Binet intelligence scales: Content and psychometrics. Stanford-Binet Intelligence Scales, Fifth Edition Assessment Service Bulletin No. 1.Greenwood J.Psychologists go to war.Behavioral Scientist.Allen G.Intelligence tests and immigration to the United States, 1900-1940.Wiley Online Library. 2006. doi:10.1002/9780470015902.a0005612American Psychological Association.IQ.Rindermann H, Becker D, Coyle T.Survey of expert opinion on intelligence: Intelligence research, experts' background, controversial issues, and the media.Intelligence. 2020;78:101406. doi:10.1016/j.intell.2019.101406Worhach J, Boduch M, Zhang B, Maski K.Remote assessment of pediatric patients with daytime sleepiness and healthy controls: A pilot study of feasibility and reliability.Child Neurol Open. 2021;8. doi:10.1177/2329048X211048064Reynolds C, Altmann R, Allen D.The problem of bias in psychological assessment.Mastering Modern Psychol Test. 2021;1621:573-613. doi:10.1007/978-3-030-59455-8_15Spielman R, Dumper K, Jenkins W, Lacombe A, Lovett M, Perlmutter M.40 measures of intelligence. Psychology - H5P Edition.van Ool J, Hurks P, Snoeijen-Schouwenaars F, et al.Accuracy of WISC-III and WAIS-IV short forms in patients with neurological disorders.Development Neurorehabil. 2018;21(2):101-107. doi:10.1080/17518423.2016.1277799Kahalley LS, Ris MD, Grosshans DR, et al.Comparing intelligence quotient change after treatment with proton versus photon radiation therapy for pediatric brain tumors.J Clin Oncol. 2016;34(10):1043-1049. doi:10.1200/JCO.2015.62.1383Holzinger A, Kickmeier-Rust M, Müller H.KANDINSKY patterns as IQ-test for machine learning.Machine Learn Knowl Extract. 2019;11713:1-14. doi:10.1007/978-3-030-29726-8_1Graham S, Depp C, Lee E, et al.Artificial intelligence for mental health and mental illnesses: An overview.Curr Psychiat Rep. 2019;21:116. doi:10.1007/s11920-019-1094-0Additional ReadingAntonson AE.Stanford-Binet Intelligence Scale.Encycloped Cross-Cultur School Psychol. 2015. doi:10.1007/978-0-387-7199-9_400Coalson DL, Raiford SE, Saklofske DH, Weiss LG.WAIS-IV: Advances in the assessment of intelligence.WAIS-IV Clin Use Interpret. 2010:3-23. doi:10.1016/B978-0-12-375035-8.10001-1Fancher RE, Rutherford A.Pioneers of Psychology(5th ed.).

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

De Boeck P, Gore LR, Gonzalez T, San Martin E.An alternative view on the measurement of intelligence and its history.Cambr Handbook Intellig. 2020:47-74. doi:10.1017/9781108770422.005Jastrzebski J, Kroczek B, Chuderski A.Galton and Spearman revisited: Can single general discrimination ability drive performance on diverse sensorimotor tasks and explain intelligence?.J Experiment Psychol. 2021;150(7):1279-1302. doi:10.1037/xge0001005Challis D.Skull triangles: Flinders Petric race theory and biometrics.Bull Hist Archaeol. 2016;26(1):p.Art.5. doi:10.5334/bha-556Terman L.The intelligence quotient of Francis Galton in childhood.Am J Psychol. 1917;28(2):209-215.Britannica.Alfred Binet: French psychologist.University of Washington.Alfred Binet’s IQ test, 1905.Becker K.History of the Stanford-Binet intelligence scales: Content and psychometrics. Stanford-Binet Intelligence Scales, Fifth Edition Assessment Service Bulletin No. 1.Greenwood J.Psychologists go to war.Behavioral Scientist.Allen G.Intelligence tests and immigration to the United States, 1900-1940.Wiley Online Library. 2006. doi:10.1002/9780470015902.a0005612American Psychological Association.IQ.Rindermann H, Becker D, Coyle T.Survey of expert opinion on intelligence: Intelligence research, experts' background, controversial issues, and the media.Intelligence. 2020;78:101406. doi:10.1016/j.intell.2019.101406Worhach J, Boduch M, Zhang B, Maski K.Remote assessment of pediatric patients with daytime sleepiness and healthy controls: A pilot study of feasibility and reliability.Child Neurol Open. 2021;8. doi:10.1177/2329048X211048064Reynolds C, Altmann R, Allen D.The problem of bias in psychological assessment.Mastering Modern Psychol Test. 2021;1621:573-613. doi:10.1007/978-3-030-59455-8_15Spielman R, Dumper K, Jenkins W, Lacombe A, Lovett M, Perlmutter M.40 measures of intelligence. Psychology - H5P Edition.van Ool J, Hurks P, Snoeijen-Schouwenaars F, et al.Accuracy of WISC-III and WAIS-IV short forms in patients with neurological disorders.Development Neurorehabil. 2018;21(2):101-107. doi:10.1080/17518423.2016.1277799Kahalley LS, Ris MD, Grosshans DR, et al.Comparing intelligence quotient change after treatment with proton versus photon radiation therapy for pediatric brain tumors.J Clin Oncol. 2016;34(10):1043-1049. doi:10.1200/JCO.2015.62.1383Holzinger A, Kickmeier-Rust M, Müller H.KANDINSKY patterns as IQ-test for machine learning.Machine Learn Knowl Extract. 2019;11713:1-14. doi:10.1007/978-3-030-29726-8_1Graham S, Depp C, Lee E, et al.Artificial intelligence for mental health and mental illnesses: An overview.Curr Psychiat Rep. 2019;21:116. doi:10.1007/s11920-019-1094-0

De Boeck P, Gore LR, Gonzalez T, San Martin E.An alternative view on the measurement of intelligence and its history.Cambr Handbook Intellig. 2020:47-74. doi:10.1017/9781108770422.005

Jastrzebski J, Kroczek B, Chuderski A.Galton and Spearman revisited: Can single general discrimination ability drive performance on diverse sensorimotor tasks and explain intelligence?.J Experiment Psychol. 2021;150(7):1279-1302. doi:10.1037/xge0001005

Challis D.Skull triangles: Flinders Petric race theory and biometrics.Bull Hist Archaeol. 2016;26(1):p.Art.5. doi:10.5334/bha-556

Terman L.The intelligence quotient of Francis Galton in childhood.Am J Psychol. 1917;28(2):209-215.

Britannica.Alfred Binet: French psychologist.

University of Washington.Alfred Binet’s IQ test, 1905.

Becker K.History of the Stanford-Binet intelligence scales: Content and psychometrics. Stanford-Binet Intelligence Scales, Fifth Edition Assessment Service Bulletin No. 1.

Greenwood J.Psychologists go to war.Behavioral Scientist.

Allen G.Intelligence tests and immigration to the United States, 1900-1940.Wiley Online Library. 2006. doi:10.1002/9780470015902.a0005612

American Psychological Association.IQ.

Rindermann H, Becker D, Coyle T.Survey of expert opinion on intelligence: Intelligence research, experts' background, controversial issues, and the media.Intelligence. 2020;78:101406. doi:10.1016/j.intell.2019.101406

Worhach J, Boduch M, Zhang B, Maski K.Remote assessment of pediatric patients with daytime sleepiness and healthy controls: A pilot study of feasibility and reliability.Child Neurol Open. 2021;8. doi:10.1177/2329048X211048064

Reynolds C, Altmann R, Allen D.The problem of bias in psychological assessment.Mastering Modern Psychol Test. 2021;1621:573-613. doi:10.1007/978-3-030-59455-8_15

Spielman R, Dumper K, Jenkins W, Lacombe A, Lovett M, Perlmutter M.40 measures of intelligence. Psychology - H5P Edition.

van Ool J, Hurks P, Snoeijen-Schouwenaars F, et al.Accuracy of WISC-III and WAIS-IV short forms in patients with neurological disorders.Development Neurorehabil. 2018;21(2):101-107. doi:10.1080/17518423.2016.1277799

Kahalley LS, Ris MD, Grosshans DR, et al.Comparing intelligence quotient change after treatment with proton versus photon radiation therapy for pediatric brain tumors.J Clin Oncol. 2016;34(10):1043-1049. doi:10.1200/JCO.2015.62.1383

Holzinger A, Kickmeier-Rust M, Müller H.KANDINSKY patterns as IQ-test for machine learning.Machine Learn Knowl Extract. 2019;11713:1-14. doi:10.1007/978-3-030-29726-8_1

Graham S, Depp C, Lee E, et al.Artificial intelligence for mental health and mental illnesses: An overview.Curr Psychiat Rep. 2019;21:116. doi:10.1007/s11920-019-1094-0

Antonson AE.Stanford-Binet Intelligence Scale.Encycloped Cross-Cultur School Psychol. 2015. doi:10.1007/978-0-387-7199-9_400Coalson DL, Raiford SE, Saklofske DH, Weiss LG.WAIS-IV: Advances in the assessment of intelligence.WAIS-IV Clin Use Interpret. 2010:3-23. doi:10.1016/B978-0-12-375035-8.10001-1Fancher RE, Rutherford A.Pioneers of Psychology(5th ed.).

Antonson AE.Stanford-Binet Intelligence Scale.Encycloped Cross-Cultur School Psychol. 2015. doi:10.1007/978-0-387-7199-9_400

Coalson DL, Raiford SE, Saklofske DH, Weiss LG.WAIS-IV: Advances in the assessment of intelligence.WAIS-IV Clin Use Interpret. 2010:3-23. doi:10.1016/B978-0-12-375035-8.10001-1

Fancher RE, Rutherford A.Pioneers of Psychology(5th ed.).

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