The history of IQ testing can be traced back to Sir Francis Galton (1822-1911). In the 1860s, Galton began studying the relationship between heredity and human ability, and he is the one who began the "nature vs. nurture" debate. He was also the first to use statistics to measure human characteristics and abilities--including intelligence. In the 1890s, one of Galton's students, James McKeen Cattell, brought intelligence testing to the United States.
In 1904, the French government commissioned Alfred Binet (1857-1911) to develop a test to measure the intelligence of school-age children. Binet developed a series of intelligence tests with the help of Theophile Simon; their tests became known as the Simon-Binet IQ Test, which became the foundation for future IQ tests.
By giving tests to certain age groups, Binet was able to determine the intelligent quotient (IQ) of an individual. For example, if 70% of 10-year-olds passed a given test, then that test represented the IQ of 10-year-olds, and a 10-year-old who passed that test was said to have an average IQ, which was scored as "100." But if an 8-year-old passed the 10-year-old test, then Binet knew that particular 8-year-old had an advanced IQ of 125 (10/8 x 100).
Alfred Binet believed that a person's intelligence quotient was a fluid reality. Thus, for Binet, the sole goal of IQ testing was to determine which students needed extra help in school. This philosophy would be rejected by later proponents of IQ testing.
Henry Goddard (1866-1957), a director of a New Jersey school, used Binet's IQ tests as an entrance exam to his school. Unlike Binet, Goddard believe a person's intelligence was fixed; therefore, a low IQ score represented an inability to learn. Goddard also classified individuals as normal, morons and idiots based on their IQ score.
During World War I, Lewis Terman (1877-1956) was commissioned by the Army to develop an IQ test to help the Army sort quickly the huge number of draftees. Terman revised Alfred Binet's IQ test and created the Stanford-Binet IQ Test. This became the standard IQ test in the United States for the next several decades and has been used by businesses and schools since.
The dark side of IQ testing is that both Goddard and Terman believed the IQ test could be used for eugenics--the systematic breeding of human beings with the goal of creating people with desired physical and intellectual traits. Because of this, IQ testing fell out of favor in the United States in the 1960s and 1970s. Today, some psychologists believe IQ testing is beneficial insofar as it can determine which students need extra help, while other psychologists believe that the tests are biased toward women and non-whites.