Goddard was one of the early Americans who worked on the question of heredity and intelligence. Goddard used Binet's scale in America and turned it into a measure of intelligence. Goddard ran an institution and also tested immigrants on Ellis Island. He became interested in Mendel's studies of genetics and peas and decided that there was one gene that was responsible for intelligence. Goddard believed that the defective people could be found through testing and then prevented from breeding so as to prevent propagation of the species. By the mid 1920s, Goddard was retracting most of what he had claimed since he knew that he had overstepped Binet's parameters for how to use the test.