Intelligence quotient (IQ) tests are commonly used to evaluate the intellectual abilities of students, job applicants, and military recruits, yet there is a compelling case against their use. IQ tests fail to accurately measure intelligence, as they assess only a narrow set of skills. With more than 200 different IQ tests available, many are deeply flawed due to the biases of their designers. In extreme instances, these tests have been crafted to single out specific groups, promoting racism, xenophobia, and even genocide.
The issue with IQ tests dates back to their inception. In the late 19th century, Sir Francis Galton of England was among the first to try quantifying intelligence, though his methods were dubious. Galton’s benchmark for intelligence was based on the traits of English noblemen, leading to the hypothesis that intelligence, like nobility, is hereditary. This linked to another of his theories, which had dangerous implications, as Galton also coined the term “eugenics,” a pseudoscience suggesting intelligence was race-related.
In 1904, Alfred Binet, a French psychologist, developed the first modern IQ test at the request of the French government to identify children needing extra help in school. Although Binet was influenced by Galton, he designed his test solely for educational purposes. Unfortunately, the framework he created was prone to misuse.
Case study: immigration tests at Ellis Island
IQ tests were introduced to the United States in a blatantly xenophobic manner. Henry H. Goddard, a psychologist and an advocate of eugenics, was the first to adapt Alfred Binet’s test for American use. In 1912, Goddard applied his test at Ellis Island to identify “feeble-minded” immigrants, whom he believed threatened the nation’s genetic pool. He argued that their descendants would likely become criminals and advocated for institutionalizing those labeled as feeble-minded to prevent reproduction, in the interest of societal well-being.
Goddard’s IQ test had a cultural bias. Originally designed for American schoolchildren using a framework from France, the test evaluated intelligence based on the educational norms of these two countries. Consequently, immigrants from different backgrounds performed poorly, leading Goddard to classify about 80% of Italian, Russian, Hungarian, and Jewish immigrants as feeble-minded. Although Goddard acknowledged that these results reflected the immigrants’ socioeconomic backgrounds rather than genetics, the tests were still used to exclude many races. Deportations due to feeble-mindedness doubled with the introduction of Goddard’s test.
Case study: U.S. Army alpha and beta tests
Henry Goddard’s work captured the attention of Robert Mearns Yerkes, President of the American Psychological Association and a member of the American Eugenics Society. During World War I in 1917, Yerkes collaborated with the Army Medical Corps to implement the “Plan for the Psychological Examining of Recruits to Eliminate the Mentally Unfit,” aiming to filter out unsuitable Army recruits. Two test versions were developed: an alpha test with written questions and a beta test featuring pictorial challenges for recruits lacking English literacy.
Throughout the war, the Army alpha and beta tests were administered to hundreds of thousands, influencing their career paths. High scores were required for officer positions. Like Goddard’s immigrant tests, these assessments favored American Anglo-Saxons, with recruits of northern European descent excelling, while black recruits and those of southern and eastern German ancestry often scored poorly. This reinforced existing hierarchies in both the military and the nation, and the tests’ perceived success bolstered the popularity of intelligence testing, embedding IQ tests in American education and employment by mid-20th century.
Case study: Virginia’s forced sterilizations
In 1924, the Virginia state legislature sanctioned the forced sterilization of hospital patients deemed unfit for reproduction, marking the most flagrant misuse of IQ testing in U.S. history. As stated in the Code of Virginia, the law targeted those labeled with “idiocy, imbecility, [and] feeblemindedness,” often determined by IQ tests. A low score could end a family line.
Virginia’s forced sterilizations led to the pivotal U.S. Supreme Court case, Buck v. Bell, in 1927, involving Carrie Buck, a 17-year-old impregnated by rape and institutionalized by her foster parents to conceal their shame. The court upheld the state’s right to sterilize Buck by an 8–1 vote, citing her child’s poor IQ test score as evidence that she could not produce mentally competent offspring.
Buck v. Bell facilitated the sterilization of 60,000 to 70,000 Americans from the 1920s to the 1970s and inspired Nazi Germany’s sterilization program. Eugenics, like craniology and phrenology, should remain in the past, yet it has endured partly due to IQ testing. When a method is so susceptible to bias, it should not be taken seriously by any scientific community.
