History of IQ test
IQ tests came into being in the early 1900s when the French government asked French psychologist Alfred Binet to build a scale or procedure to determine which students would face the most difficulty in school, so that an elaborate plan could be developed to support their studies. He invented the Binet-Simon scale with the help of his colleague Theodore Simon using a framework that provided the basis for modern-day IQ testing. What started out as a practice to determine which students would require special assistance in school became the basis for inferring human intelligence, a practice which continues to be used around the world today.
What did it cover?
Questions that focused on attention, memory, and problem solving were included within the first iteration of the test. One of Binet’s initial conclusions was that some students were capable of answering more questions in a rapid timeframe ,while others struggled with this approach. Using this concept, he developed the idea of mental age to determine which students were more likely to excel in their school life.
How did this evolve into the IQ test of today?
Following the growing popularity of the Binet-Simon scale, Standford University psychologist Lewis Terman, took the Binet-Simon Scale and standardized it using a sample of American participants. The next iteration of the test, known as The Stanford-Binet Intelligence Scale, became the standard intelligence test used in the US in 1916.
The Stanford-Binet test led to the formulation of the term Intelligence Quotient which consisted of a single number, known as IQ. This number represented an individual’s performance across a spectrum of possibilities in the Stanford-Binet test. The score was generated by dividing the test maker’s mental age by their physical age and the multiplying the result by 100. To illustrate, if a child exhibited a mental age of 14 from the test and they were 10 years old, their final IQ score would be 140.
The Stanford-Binet remains a popular method of intelligence assessment today and has gone through a number of iterations over the years since its inception.