Who modified the Intelligence Quotient (IQ) formula?
Detailed Explanation & Solution
📌 Core Theoretical Concept:
The modified and modern formula for Intelligence Quotient (IQ) was developed by the American psychologist Lewis Terman. Originally, the concept of Mental Age was introduced by Alfred Binet. Later, in 1912, German psychologist William Stern proposed the initial IQ formula as Mental Age divided by Chronological Age ($IQ = \frac{MA}{CA}$). However, to eliminate fractions and make the scores easier to interpret, Lewis Terman of Stanford University modified this formula in 1916 by multiplying it by 100 ($IQ = \frac{MA}{CA} \times 100$). This revised formula became the standard for the Stanford-Binet Intelligence Scale, making Terman the correct answer for modifying the formula.
📊 Key Exam Points:
- Lewis Terman: Modified the IQ formula by multiplying by 100 for the Stanford-Binet Scale in 1916.
- William Stern: Originally proposed the concept and initial ratio formula of IQ in 1912.
- Alfred Binet: Known as the father of intelligence testing, who created the first formal intelligence scale in 1905.
- Wechsler: Developed individual intelligence scales such as WAIS and WISC, departing from the ratio IQ method for adults.
📖 Theoretical Reference: Intelligence testing and its historical evolution form a core topic in educational psychology. Understanding the exact contributions of Stern and Terman helps educators classify cognitive abilities efficiently. Read more about Intelligence Theories and Measurement.
🎯 Exam Perspective: Key Insights for Teacher Exams Detailed Solution ➔
Deep Pedagogical Analysis:
Teacher eligibility tests (like CTET, UPTET, DSSSB, and KVS) frequently test candidates on the distinction between the originator of the IQ concept and the person who modified the formula. Aspirants must carefully note that William Stern formulated the foundational concept, whereas Lewis Terman introduced the multiplier of 100 to create the universally recognized modern formula. Recognizing these subtle differences prevents common negative marking pitfalls in competitive educational examinations.