Eugenics + Standard IQ Test
Claims that races have different intelligence were used to justify colonialism, slavery, social Darwinism, and racial eugenics. The first practical intelligence test was developed by Alfred Binet (1905) in France for school placement of children. Binet’s test was translated into English and repurposed in 1916 by Lewis Terman (who introduced IQ scoring for the test results) and was published under the name the Stanford–Binet Intelligence Scales.
In the 1920s, states like Virginia enacted eugenic laws, such as its 1924 Racial Integrity Act, which established the one-drop rule as law. On the other hand, many scientists objected and pointed to the contribution of environment (such as resources or speaking English as a second language). Discussion of the issue in the U.S. was also influenced by German Nazi claims of a “master race”.
In the 1960s, William Shockley revived public debated about the different intelligence levels of races. Arthur Jensen stimulated scholarly discussion of the issue with his Harvard Education Review article, “How Much Can We Boost IQ and Scholastic Achievement?” Jensen’s article questioned remedial education for African American children, suggesting their poor educational performance reflects an underlying genetic cause rather than lack of stimulation at home. Jensen continued to sucessfully publish on the issue until his death in 2012.