Binet-Simon Scale (1905): The Test That Started It All

About the 1905 Binet-Simon Scale

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.

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.