- Large-scale IQ tests of United States Army recruits in World War I showed that Blacks scored considerably lower than native-born whites
- Rushton & Jensen (2005) write that, in the United States, self-identified blacks and whites have been the subjects of the greatest number of studies. They state that the black-white IQ difference is about 15 to 18 (whites scoring higher)
- Using data primarily from the United States and Europe, Jensen and Rushton have estimated the average IQ of Blacks/Africans to be around 85; of whites/Europeans to be around 100.