Definition of intelligence quotient

The concept of intelligence testing dates back to the early 20th century when psychologist Alfred Binet was tasked with developing a method to identify children who needed additional educational support in France. Binet's original scale provided a range of scores based on a child's ability to answer a series of questions, but the inconsistencies and limitations of these scores led to the development of a more standardized system. In 1912, Thomas U. Ford, an American psychologist, suggested that the age-score relationship could be transformed into a type of quotient, much like how height can be converted into a quotient using age as the denominator. This gave birth to the Intelligence Quotient (IQ) score. The IQ score was calculated by dividing an individual's mental age, as determined by their performance on the test, by their chronological age and multiplying by 100. The IQ score remained a popular method for measuring intelligence throughout the 20th century, despite criticisms of its reliability and validity, mainly due to cultural and social biases in the test questions. However, modern intelligence tests aim to minimize these issues, and the IQ score continues to be a widely used tool in cognitive assessments, educational evaluations, and various other applications.