Stanford-Binet Intelligence Scales

The Origin of the Stanford-Binet Intelligence Scales

The Stanford-Binet Intelligence Scales is a standardized test that measures intelligence and cognitive abilities in children and adults. Its roots go back to early 20th-century France, where psychologist Alfred Binet was commissioned by the government to identify students who needed special educational assistance.

In 1916, Lewis Terman of Stanford University adapted the Binet-Simon scale for use in the United States, creating the first “Stanford-Binet” test. This version introduced the concept of the Intelligence Quotient (IQ), calculated by dividing a person’s mental age by their chronological age and multiplying by 100.

Evolution of the Test

Since its inception, the Stanford-Binet has undergone five major revisions (SB5 is the current version). While the original test focused heavily on verbal skills, modern versions measure five key “factors” of cognitive ability:

1. Fluid Reasoning: The ability to solve novel problems.
2. Knowledge: General information and vocabulary.
3. Quantitative Reasoning: Mathematical thinking and problem-solving.
4. Visual-Spatial Processing: Understanding patterns and spatial relationships.
5. Working Memory: The capacity to hold and manipulate information.

How the Stanford-Binet Differ from the WAIS

While both the Stanford-Binet and the WAIS (Wechsler Adult Intelligence Scale) are considered gold standards in psychometry, they have key differences:

• Age Range: The Stanford-Binet can be used for individuals as young as 2 years old up to 85+, making it more versatile for pediatric testing than the WAIS.
• Subtest Structure: The Stanford-Binet uses a more “fluid” structure, often adjusting the difficulty of tasks in real-time based on the test-taker’s performance (routing), which can make the testing process more efficient for extremely high or low IQ individuals.
• Measurement of the Gifted: Historically, the Stanford-Binet has been favored for identifying “giftedness” and genius because of its higher ceiling and sensitivity in the upper percentiles.

The Significance of the “IQ” Formula

It was the Stanford-Binet that popularized the number we now recognize as the IQ score. Terman’s formula ($Mental Age / Chronological Age \times 100$) standardized the results so that an “average” person would always score 100. While modern tests use a different statistical method (Deviation IQ based on the Bell Curve), the legacy of the original Stanford-Binet quotient remains deeply embedded in our culture.

Conclusion: A Century of Insight

For over 100 years, the Stanford-Binet has provided a window into the human mind. From its humble beginnings as a tool for educational support to its current status as a sophisticated measure of human potential, it remains a pillar of psychology. In our IQ Archive, many of the classical figures’ scores were obtained using earlier versions of this legendary scale.