Yerkes was a prominent psychologist who, during World War I, developed the Army Alpha and Beta tests, which were designed to assess the mental abilities of recruits. After the war, he became a proponent of using these tests, or similar ones, to screen immigrants. He believed that these tests could identify those who were "feebleminded" and therefore unfit for American society.
It's important to note that Yerkes's views were highly controversial and have been widely criticized for their racist and discriminatory nature. The tests were biased against immigrants who were not native English speakers and who came from different cultural backgrounds. They were used to justify discriminatory immigration policies and were a key part of the eugenics movement, which sought to improve the human race through selective breeding.
It's crucial to understand that Yerkes's views were based on flawed assumptions and have no scientific validity. The use of intelligence tests to screen immigrants was a discriminatory practice that had a lasting negative impact on American society.