A Complete Guide to Understanding the Stanford-Binet Test

Learn more about the Stanford-Binet test, the first IQ test, which opened the door to IQ testing and expanded our understanding of cognition.

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The Stanford-Binet test is the first official IQ test, developed when measuring intelligence was still in its infancy. However, although it has existed for over a century, it is still one of the most popular and widely used IQ tests in the world, which is a testament to its quality.

To gain a deeper insight into the oldest IQ test still in use, we’ve consulted our experts and asked them how it was developed, what its uses today are, and whether it has any limitations worth mentioning.

In this article, we will review what they’ve told us.

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Key takeaways

Key Takeaways

  • The Stanford-Binet test is the first-ever IQ test that’s still used to assess cognitive development and measure IQ to this day.
  • The creator of the original Binet test was French psychologist Alfred Binet, but the actual Stanford-Binet test was developed when a Stanford professor translated the test from French.
  • In the past, the test relied on mental age to calculate IQ scores, but now it compares each test taker’s performance to their peer group’s.
  • The Stanford-Binet test is somewhat limited because it doesn’t take all kinds of intelligence into account, nor is it fully culture-neutral.

What Is the Stanford-Binet Test?

What Is the Stanford Binet Test?

What Is the Stanford Binet Test?

The Stanford-Binet test is the first official IQ test, published in 1916 after Stanford professor Lewis Terman translated Alfred Binet’s original test from French. Since then, it’s gone through several revisions, the one currently in use being the fifth edition.

This latest edition of the Stanford-Binet test includes questions that measure five factors of intelligence: fluid reasoning, working memory, quantitative reasoning, knowledge, and visual-spatial processing.

Furthermore, all of these factors come in two subsets: verbal and nonverbal. As a result, it can be used across various cultures and age ranges.

And speaking of age ranges, the Stanford-Binet test has a very wide one. According to the official description of the test, it can be administered to everyone older than two.

Considering its versatility and accuracy, it’s widely used for school placement, diagnosing cognitive and learning disabilities, as well as assessing candidates in the job hiring process.

Alfred Binet and the Creation of the Stanford-Binet Test

In its original French form, the Stanford-Binet test was developed by the aforementioned French psychologist Alfred Binet, who wanted to determine which children needed extra help with their learning.

Although he’s now renowned as a psychologist, Binet didn’t follow that path from the beginning.

In fact, he was pursuing a law career when he came across research on hypnosis by French neurologist Jean-Martin Charcot in 1878. This topic fascinated him so much that he decided to devote himself entirely to the study of psychology.

Over the years, he performed numerous experiments, attempting to measure higher mental processes and reasoning ability. Then, in 1895, he founded the first French journal on psychology—L’Année psychologique.

Thanks to his contributions to the developing field of psychology in France, he was the government’s first choice when it needed someone to develop a way to identify children with potential cognitive disabilities. This happened in 1904, when education became mandatory and children of all backgrounds started attending school.

Along with his colleague, Theodore Simon, Alfred Binet created a test with 30 questions, which became the first-ever IQ test. At the time, Binet also developed the concept of mental age, allowing him to determine how advanced each test taker’s cognition was.

The IQ Test Predecessors

Although Binet’s test was undoubtedly the first proper IQ test, it wasn’t the first to attempt to measure intelligence and cognitive development.

In fact, his research was largely inspired by Francis Galton, a British anthropologist whose goal was to classify humans according to intelligence and personality traits.

Francis Galton himself actually drew inspiration from Charles Darwin and his categorization of animals.

He believed that humans could be similarly classified as long as there was a reliable way to measure mental processes. Since he set out to develop one, he became known as the father of psychometrics.

However, Galton’s methods were somewhat primitive and unreliable—hardly surprising when he was a pioneer in his field. Still, they built a foundation for future psychologists, such as James McKeen Cattell, who developed mental tests that directly inspired Binet's first IQ test.

Stanford-Binet Test: The Intelligence Scale

an image of a test answer sheet

an image of a test answer sheet

The original Binet test became so well known that it crossed the ocean and took root on American soil. Initially, eugenicist and segregationist Henry Goddard introduced it to the American public, but, as mentioned above, the first official translation was done by Stanford professor Lewis Terman.

Since then, the Stanford-Binet test has remained one of the most widely used and popular tests in the world. However, the test we use today isn’t exactly the same as the one Terman published in 1916, nor does it use measuring methods.

For instance, scores on the Stanford-Binet test used to be calculated using Binet’s concept of mental age.

Basically, if a 10-year-old child performed as well as a 13-year-old, their mental age would be 13. Then, 13 would be divided by 10, and the result would be multiplied by 100 to get the final score. In this case, that’s an IQ of 130.

Nowadays, the Stanford-Binet test calculates IQ in the same way most other IQ tests do: by comparing each test taker’s performance to that of their peers. That’s expressed in percentiles, which are then converted to a score on a scale from 40 to 160.

Check Where You Rank on the Intelligence Scale

Like all standardized tests, the Stanford-Binet Intelligence Scale costs hundreds of dollars to take. Yet, our free IQtest.net can measure the development of your cognitive skills just as precisely, using the latest psychometric methods to calculate your IQ.

Plus, since it’s free, you can retake the test as many times as you need to train your cognition and boost your score. Make sure to test yourself frequently and track your progress as well.

The Limitations of the Stanford-Binet Test

The limitations of the Stanford-Binet test were obvious even to Binet himself—he claimed intelligence was too broad and complex to measure with a simple test or express using a single score.

However, since he had no better way of measuring it, he had to leave his work somewhat incomplete.

In addition, here are some further limitations of the Stanford-Binet test:

  • Doesn’t consider different aspects of intelligence. The Stanford-Binet test measures only one part of intelligence while neglecting other aspects, such as emotional intelligence or any of Gardner's nine intelligence types. Yet, these are just as crucial as the ones measured on the Stanford-Binet.
  • Not actually culture-neutral. Although non-verbal parts of the Stanford-Binet may be considered culture-neutral, that’s not really the case—the influence of the Western school of thought can’t be entirely avoided. As a result, people from cultures that don’t have similar ways of thinking may perform worse.

Wechsler Intelligence Scales

an image of a test answer sheet in the Stanford Binet test

an image of a test answer sheet in the Stanford Binet test

The limitations of the original Stanford-Binet test were clear to another psychologist interested in measuring intelligence—David Wechsler. Dissatisfied with Binet’s timed tasks and a single-score approach, he developed the Wechsler-Bellevue Intelligence Scale in 1939.

Then, ten years later, Wechsler set out to create a separate test just for children—the Wechsler Intelligence Scale for Children. This test was essentially an adaptation of several subtests from the original 1939 test, but it included a few additional subtests specifically made for it.

However, his work didn’t end there. In 1955, he decided to improve upon the Wechsler-Bellevue Intelligence Scale, which ultimately resulted in the new Wechsler Adult Intelligence Scale (WAIS).


Currently, WAIS-IV, the newest edition of the original WAIS, is the most popular and widely used IQ test in the world. Although Wechsler initially disliked timed tasks and a single score to represent all intelligence, both features are present in the WAIS-IV.

Furthermore, WAIS-IV tests four broad intelligence components, including the Verbal Comprehension Index, the Working Memory Index, the Perception Reasoning Index, and the Processing Speed Index. At the end, the scores from each of these subsets are combined into a single, final result.

As its name indicates, WAIS-IV is administered only to adults over 16. In all other cases, psychologists use the Wechsler Intelligence Scale for Children, which is appropriate for the 6–16 age range.

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Final Thoughts

Without the Stanford-Binet test, it’s difficult to say whether IQ testing would have developed as much as it has and which direction it would have taken.

After all, many IQ tests that followed were created as a response to the original test, attempting to correct what their creators perceived as its limitations and deficiencies.

Plus, despite its imperfections, the Stanford-Binet test still holds its own among the numerous new options for intelligence testing. It is still considered one of the best IQ tests in the world, as evidenced by the fact that it’s so widely used in schools, workplaces, and other settings.

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