Please forward this error screen to 64. Scores from intelligence tests are estimates of intelligence. Unlike, for example, distance and mass, a concrete measure of intelligence cannot be achieved given the abstract nature of the concept of “intelligence”. IQ scores are used for educational placement, assessment of mathematics for children with mental retardation class 1 disability, and evaluating job applicants.
Even when students improve their scores on standardized tests, they do not always improve their cognitive abilities, such as memory, attention and speed. Historically, even before IQ tests were devised, there were attempts to classify people into intelligence categories by observing their behavior in daily life. The English statistician Francis Galton made the first attempt at creating a standardized test for rating a person’s intelligence. French psychologist Alfred Binet, together with Victor Henri and Théodore Simon had more success in 1905, when they published the Binet-Simon test, which focused on verbal abilities. Goddard published a translation of it in 1910. The many different kinds of IQ tests include a wide variety of item content. Some test items are visual, while many are verbal.
Test items vary from being based on abstract-reasoning problems to concentrating on arithmetic, vocabulary, or general knowledge. The British psychologist Charles Spearman in 1904 made the first formal factor analysis of correlations between the tests. Spearman’s argument proposing a general factor of human intelligence is still accepted in principle by many psychometricians. During World War I, a way was needed to evaluate and assign Army recruits to appropriate tasks.
This led to the development of several mental tests by Robert Yerkes, who worked with major hereditarians of American psychometrics—including Terman, Goddard—to write the test. At the start of the war, the army and national guard maintained nine thousand officers. By the end, two hundred thousand officers presided, and two- thirds of them had started their careers in training camps where the tests were applied. In some camps, no man scoring below C could be considered for officer training. 75 million men were tested in total, making the results the first mass-produced written tests of intelligence, though considered dubious and non-usable, for reasons including high variability of test implementation throughout different camps and questions testing for familiarity with American culture rather than intelligence. The results of these tests, which at the time reaffirmed contemporary racism and nationalism, are considered controversial and dubious, having rested on certain contested assumptions: that intelligence was heritable, innate, and could be relegated to a single number, the tests were enacted systematically, and test questions actually tested for innate intelligence rather than subsuming environmental factors. While not widely used, Thurstone’s model influenced later theories.