About the 1905 Binet-Simon Scale
The Binet-Simon Scale, published in 1905 by French psychologist Alfred Binet and physician Theodore Simon, was the first practical intelligence test and introduced the idea of measuring a child's mental age, making it the direct ancestor of the Stanford-Binet and every modern IQ test.
In 1904 the French Ministry of Public Instruction asked Alfred Binet to find a way to identify children who would not benefit from ordinary schooling and should be moved to special-education classes. The existing methods (teacher judgment, parent interviews) were too subjective. Binet, with his collaborator Theodore Simon, set out to build something objective.
What they produced in 1905 was the first practical intelligence test. Thirty items arranged in order of increasing difficulty. The test was given individually by a trained examiner using simple physical materials: food, candles, weighted boxes, pictures, paper. Each item was carefully selected so that, on average, children of a certain age could solve it. By finding the highest item level a child could pass, the examiner could estimate the child's mental level (later called mental age) and compare it to the child's chronological age.
The Binet-Simon scale was revolutionary for three reasons:
- It was empirical. Binet didn't theorize about intelligence; he just tested children and kept the items that discriminated between age groups.
- It focused on judgment. Binet explicitly placed judgment above memory, sensory acuity, or rote knowledge as the core of intelligence. (Read his quotation in the volume: "To judge well, to comprehend well, to reason well, these are the essential activities of intelligence.")
- It was diagnostic, not eugenic. Binet built the test to identify children who needed extra help, not to rank or sort populations. He explicitly warned against treating IQ as a fixed property of the person. Most of what followed in IQ testing's eugenic period (Goddard, Terman, Yerkes) departed from Binet's stated intentions.
The 1905 scale was revised in 1908 (introducing age levels formally) and 1911 (the year of Binet's death). Lewis Terman's 1916 Stanford Revision took the 1911 scale, expanded it, normed it on American children, and introduced the formula IQ = (mental age ÷ chronological age) × 100. That formula was born from Binet's scale, but Binet himself never used it.
All 30 items in the 1905 scale
The complete list of Binet and Simon's original 30 tests, in the order they were given. Items requiring physical materials or an examiner are marked accordingly.
Take the interactive subset
The items below are the verbal and reasoning tests from the 1905 scale that can be self-administered in a browser. Each item is multiple-choice with one best answer per Binet's original scoring criteria.
No data leaves your browser. Your answers stay local.
Read the Original
The following are legitimate free or borrowable full-text sources for this test or its primary documentation:
Source and verification
All items, descriptions, and the historical material on this page are transcribed from:
Binet, A. & Simon, T. (1916). The Development of Intelligence in Children (The Binet-Simon Scale). Translated by Elizabeth S. Kite. Baltimore: Williams & Wilkins Company. Originally published in L'Année Psychologique, 1905, Vol. XII.
The Kite translation is the standard English-language edition of Binet and Simon's work. It is in the public domain in the United States (published before 1929). The full book is on Internet Archive: archive.org/details/b32756355.
The 1905 paper itself ("Méthodes nouvelles pour le diagnostic du niveau intellectuel des anormaux") appeared in L'Année Psychologique, Vol. 11, pp. 191-244. The Kite volume reproduces it along with Binet's 1908 and 1911 revisions and extensive practical instructions.
Frequently asked questions
What is the Binet-Simon Scale?
The Binet-Simon Scale is the first practical intelligence test, published in 1905 by Alfred Binet and Theodore Simon in France. It consisted of a graded series of tasks of increasing difficulty, ranging from simple actions like following a light with the eyes to more complex reasoning, memory, and judgment problems. Rather than measuring physical traits, it assessed higher mental functions, and it became the foundation on which all later IQ tests were built.
Who created the Binet-Simon Scale and why?
It was created by psychologist Alfred Binet and his collaborator, physician Theodore Simon. The French government had asked Binet to find a way to identify schoolchildren who needed extra educational support. The 1905 scale was designed to distinguish children who were struggling for reasons of ability from those held back by other factors, so they could receive appropriate help rather than be left behind in ordinary classrooms.
What did the Binet-Simon Scale measure, and how was it scored?
The scale measured reasoning, judgment, memory, and comprehension through about 30 tasks ordered from easiest to hardest. Its key innovation, refined in the 1908 revision, was the concept of mental age. A child's performance was compared with the typical performance of children at each age, so a child who passed the tasks a typical eight-year-old could pass was assigned a mental age of eight, regardless of actual age. Binet deliberately did not produce a single fixed number he called intelligence; he saw the result as a practical guide, not a permanent label.
Did the Binet-Simon Scale produce an IQ score?
No. The original Binet-Simon Scale produced a mental age, not an intelligence quotient. The IQ itself came later. In 1912 German psychologist William Stern proposed dividing mental age by chronological age, and in 1916 Lewis Terman at Stanford University multiplied that ratio by 100 to create the familiar IQ score as part of his Stanford-Binet revision. Binet's scale supplied the mental-age concept that made the IQ formula possible.
How is the Binet-Simon Scale related to modern IQ tests?
It is the direct ancestor of nearly all of them. Lewis Terman adapted and standardized the Binet-Simon Scale for American use, releasing it in 1916 as the Stanford-Binet Intelligence Scales, which became one of the most widely used IQ tests in the world. The Stanford-Binet is still published today in revised editions, and its lineage traces straight back to Binet and Simon's 1905 work. Modern tests such as the Wechsler scales were developed partly in response to the Binet tradition.
Is the original 1905 Binet-Simon Scale still used today?
Not in its original form. The 1905 scale and its 1908 and 1911 revisions are now of historical interest, since their content and norms are well over a century old. Its method lives on, however, through the continuously updated Stanford-Binet Intelligence Scales and the broader field of standardized cognitive testing it founded. Anyone wanting a valid result today should take a current professionally normed test rather than the 1905 original.
Cite this page
This page is part of the Historical IQ Tests Archive. Editorial content, transcription notes, and curation are released under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). Public-domain primary sources retain their public-domain status. BibTeX · RIS
Historical test materials are obsolete and are not valid modern IQ assessments. This page is preserved for educational, research, and historiographic purposes.
Looking for a contemporary IQ test?
The instrument documented above is a historical document. Modern IQ scoring uses contemporary norms (mean 100, SD 15). Our free full IQ test is available separately.