History of IQ Tests

The history of IQ tests stretches back only 100 years, even though the idea of measuring human intelligence has fascinated man for centuries. Today, the Internet has made IQ tests more accessible — and popular — than ever.

With the variety of free IQ tests available online, anyone who is curious has a chance to learn their IQ quickly and easily.

That wasn’t always the case. IQ tests used to be delivered mainly in schools, where they were used primarily to determine how “trainable” a student might be.

The history of IQ tests can be traced back to the late 1800s. Sir Francis Galton, a British cousin of Charles Darwin, became fascinated with the aftermath of Darwin’s work on evolution. Throughout his career Galton worked to identify the role of heredity in human ability.

Galton’s work — considered by many to be the first scientific investigation into human intelligence — was published in a book entitled Hereditary Genius.

Galton’s work found its way to the United States through one of his students, James Cattell. In the history of IQ tests, it was Cattell’s work and interest that eventually led to the introduction of experimental psychological testing among the American population.




About the same time in France, a psychologist named Alfred Binet was developing a test to measure children’s intelligence. His tests were first used in 1904.

Binet’s intent was to develop a method of measuring a child’s educational potential, so that children could receive the support and assistance they needed.

His tests gave children a “mental age” that reflected their intellectual capabilities, and helped to place them in appropriate learning environments.

The Advent of IQ Termites

Lewis Terman, an American psychologist, is credited with coining the term “intelligent quotient,” or IQ. Terman’s early work included studying a group of boys — Terman’s Termites — some of whom he considered bright; others, stupid.

Eventually, Terman went on to adapt the Binet test to form the Stanford-Binet, which is still in use today, almost a century later.

IQ tests history in the United States took a dramatic turn in 1917. As America joined World War 1, there was no efficient, standardized method of classifying and assigning the men who were being put into service.



Lewis Terman and a former pupil developed an intelligence test that was eventually used with almost 2 million American men between 1917 and 1919.

After the successful use of IQ testing during the First World War, IQ tests reached incredible popularity not only within the school system, but also as workers were being recruited for jobs in post-war America.

In the 1940s, the history of IQ tests took another turn as psychologist David Wechsler developed a new series of comprehensive, multifaceted tests designed to measure intelligence and abilities.

The Wechsler Adult Intelligence Scale remains one of the standards in IQ measurement today.

The history of IQ tests is not without controversy. In his work, Lewis Terman was determined to use IQ testing to help “weed out” the undesirable elements of society. He argued that the use of IQ testing would protect the gene pool, reduce crime and improve levels of morality.

Today, IQ tests are often used to help measure a student’s potential, and to help determine an appropriate career path. They are rarely used for employment testing anymore, however.

history of IQ testsStill, every year, millions of Americans undergo IQ testing. The history of IQ tests shows that though critics of IQ testing caution against labeling and limiting individuals, IQ tests remain the standard measurement for placing students within classrooms to this day.

History of IQ Tests: Greatest Minds Of All Time

If you are interested in learning more about the IQ test scores of some of the world’s greatest thinkers, this chart helps put it all into perspective.

There’s some debate about who has scored the highest IQ of all time. Many experts credit writer Marilyn vos Savant with this achievement. She registered a score of 228 on an IQ test when she was 10 years old, and has gone on to great acclaim for her intellect.

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