HISTORY OF IQ

INTRODUCTION
The concept of Intelligence Quotient, or IQ, has fascinated scientists, educators, and the general public for more than a century. IQ is a numerical representation of human intelligence derived from standardized tests. While today it’s a common term, the history of IQ testing is deeply connected to developments in psychology, education reform, and even military planning. Understanding its history helps explain how IQ came to be used, adapted, and sometimes criticized.

EARLY IDEAS ABOUT INTELLIGENCE
Long before formal IQ tests existed, philosophers and scholars debated the nature of intelligence. Ancient Greek thinkers like Plato and Aristotle explored whether intelligence was innate or learned. In the 19th century, with the rise of modern psychology, researchers began seeking measurable ways to assess mental ability.

FRANCIS GALTON AND THE FIRST ATTEMPTS
In the late 1800s, Sir Francis Galton, a British polymath and cousin of Charles Darwin, was among the first to attempt measuring intelligence scientifically. Galton believed that intelligence was hereditary and could be measured through sensory perception and reaction times. Although his methods were primitive, they laid the groundwork for the idea that mental ability could be quantified.

THE BIRTH OF THE IQ TEST – ALFRED BINET
The true beginning of IQ testing came in the early 20th century with Alfred Binet, a French psychologist. In 1904, the French government asked Binet and his colleague Théodore Simon to develop a method for identifying children in need of special education. The result was the Binet-Simon scale, the first practical intelligence test.
Binet’s test measured skills like memory, attention, and problem-solving rather than physical traits. He also introduced the idea of “mental age” – comparing a child’s test performance to the average performance of children at different ages.

WILLIAM STERN AND THE IQ FORMULA
In 1912, German psychologist William Stern coined the term “Intelligence Quotient.” Stern proposed a formula: IQ = (Mental Age ÷ Chronological Age) × 100. This meant that a child whose mental age matched their actual age would have an IQ of 100.

ADAPTATION IN THE UNITED STATES – LEWIS TERMAN
In 1916, American psychologist Lewis Terman at Stanford University adapted and revised Binet’s test for use in the United States, creating the Stanford-Binet Intelligence Scale. This version became the foundation of IQ testing in America and was used widely in schools.

WORLD WAR I AND MASS TESTING
During World War I, the U.S. Army used IQ tests (Army Alpha and Beta tests) to screen and classify soldiers. This was the first large-scale application of intelligence testing and introduced the concept to the broader public.

DAVID WECHSLER AND MODERN IQ TESTS
In the 1930s and 1940s, psychologist David Wechsler developed new intelligence scales, including the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Intelligence Scale for Children (WISC). These tests measured both verbal and non-verbal abilities and are still widely used today.

CHANGES AND CRITICISMS
Over the years, IQ testing has evolved, but it has also faced criticism. Some argue that IQ tests can be culturally biased, not capturing the full range of human intelligence. Others point out that creativity, emotional intelligence, and social skills are equally important but not measured by traditional IQ tests.

IQ IN THE 21ST CENTURY
Today, IQ tests are used in education, clinical psychology, and research. Digital technology has made IQ testing more accessible online, but professional administration is still preferred for accuracy. Researchers continue to study the nature of intelligence and how it relates to genetics, environment, and life success.

CONCLUSION
The history of IQ is a story of scientific curiosity, educational reform, and the ongoing search to understand human intelligence. From Galton’s early experiments to modern standardized tests, IQ has remained a key, though sometimes controversial, measure of mental ability. Knowing this history allows us to appreciate both the strengths and limitations of IQ testing in understanding human potential.