The Stanford-Binet Intelligence Scales are one of the oldest and most respected measures of cognitive ability in the world. The name reflects the test’s dual heritage — a French psychologist who created the original and an American university that adapted it for the United States.
Origins of the Stanford-Binet Test
In 1905, the French government asked psychologist Alfred Binet to develop a method for identifying students who needed extra academic support. Together with his colleague Theodore Simon, Binet created the Binet-Simon Scale — the world’s first standardized intelligence test.
Because Binet and Simon could not identify a single marker of intelligence, they devised a system that compared a child’s performance to age-based expectations. From this data, they established a baseline from which cognitive ability could be measured. The approach was groundbreaking: rather than testing what children had been taught, it attempted to measure how they thought.
The Binet-Simon Scale quickly earned recognition from the psychology community. It was designed to be adaptable across languages and cultures, which accelerated its international adoption.
Stanford University and the Binet-Simon Scale
The work of Binet and Simon was quickly picked up by Lewis M. Terman, a psychologist at Stanford University. In 1916, Terman published his American adaptation — standardized against a large U.S. sample — as the Stanford-Binet Intelligence Scale. His publication, “The Measurement of Intelligence,” established the framework that would guide intelligence testing for the next century.
Key Figure
Terman’s 1916 adaptation transformed a French diagnostic tool into the most widely used intelligence test in the United States, establishing the partnership between European origins and American standardization that has continued through every subsequent edition.
The Addition of Intelligence Quotient
In the immediate aftermath of the Binet-Simon and Stanford-Binet developments, different rating scales were being used to quantify results, creating confusion. German psychologist William Stern proposed a solution: the Intelligence Quotient, or IQ, which compared a child’s mental age (as measured by the test) to their biological age to produce a ratio score.
Terman adopted the IQ concept immediately, and it became the standard way to express Stanford-Binet results. The ratio IQ was eventually replaced by the deviation IQ in later editions — a statistical score with a mean of 100 and standard deviation of 15 — which remains the standard today.
Subsequent Editions of the Stanford-Binet Test
The Stanford-Binet has undergone five major revisions, each incorporating advances in cognitive science and psychometric methodology:
| Edition | Year | Key Development |
|---|---|---|
| Binet-Simon Scale | 1905 | First standardized intelligence test |
| Stanford-Binet (Terman) | 1916 | Adapted for American use; introduced the IQ ratio |
| SB-2 (Terman-Merrill) | 1937 | Two parallel forms; improved standardization |
| SB-3 | 1960 | Single form; deviation IQ scoring replaces ratio IQ |
| SB-4 | 1986 | Point-scale format; expanded age range |
| SB5 (current) | 2003 | CHC theory; five factors × verbal/nonverbal; adaptive routing |
Current Edition
The Fifth Edition (SB5), published by Dr. Gale H. Roid, introduced a five-factor cognitive model with both verbal and nonverbal subtests for every factor, updated norms, and gifted composite scores — making it the most comprehensive version in the test’s history. A sixth edition (SB6) is in development, with field testing underway by PRO-ED.
What the Stanford-Binet Is Not
Understanding what the Stanford-Binet is not is just as important as understanding what it is:
Not an online test
The SB5 is individually administered — a trained professional sits with one examinee at a time, presents materials, and scores responses in real time. There is no group-administered version, no paper-and-pencil version, and no legitimate online version.
Not a timed race
While some subtests have time-sensitive components, the SB5 is designed to measure how well you can think, not how fast. Most examinees complete the full battery in 45 to 90 minutes.
Not a school exam
While the Knowledge factor draws on accumulated learning, the majority of the SB5 measures how you think, not what you know. Fluid Reasoning, Visual-Spatial Processing, and Working Memory are largely independent of formal education.
Not a permanent measurement
IQ scores can change over time, particularly in childhood. A score at age 4 is less predictive of adult ability than a score at age 10. The SB5 provides a snapshot of cognitive functioning at a specific moment — not a destiny.
For a complete overview of the five cognitive factors and how they’re tested, see our guide to what the Stanford-Binet measures.