Consulting published and unpublished sources, Richardson establishes a chronology of Knox's life, including details of his medical training and his time as a physician for the U.S. Army. He describes the conditions that gave rise to intelligence testing, including the public's concern that the United States was opening its doors to the mentally unfit. He then recounts the development of intelligence tests by Knox and his colleagues and the widely-discussed publication of their research. --from publisher description.