Dr. McGurk’s analysis of the professional literature in this field closely parallels Dr. Shuey’s report. Between 1935 and 1950, he has stated, sixty-three articles appeared in professional journals of psychology dealing with Negro-white test-score differences. _In all sixty-three of them_, the average test score of the Negro subjects was found to be lower than the average test score of the white subjects with whom they were compared. Six of these investigations are regarded by McGurk as especially significant: 1. A study of a group of Canadian Negroes and whites in 1939 by H. A. Tanser. The Negro children tested were the descendants of slaves who had escaped from the South prior to and during the Civil War. Their social and economic opportunities had been generally equal to those of whites in the area. Yet the findings of three standard psychological tests administered to children in grades 1-8 found the Negro averages far below the white averages at every age and every grade. For the total groups, only 13 to 20 per cent of the Negroes overlapped the white average, and in no case did the overlap exceed 20 per cent. 2. A study of white and Negro children in a poor section of rural Virginia, done by M. Bruce in 1940. In order to eliminate the factor of social and economic differences, the author first administered a test of socio-economic status, and then paired off her subjects so that each member of a pair, one Negro child and one white child, had the same socio-economic score. Negro overlapping on three separate tests ranged between 15 per cent and 20 per cent. 3. A study by Dr. Shuey of white and Negro college students in New York, in 1942. Again, the Negro and white students were first given socio-economic tests in order to pair them off. The Negro overlap amounted to 18 per cent. Of this investigation, Dr. McGurk says: “Considering that this was a highly selected group of college students, such low overlapping is surprising. It does not lend credence to the belief that socio-economic factors are responsible for the Negro-white differences in psychological test performance.” 4. A study of white and Negro kindergarten children in Minneapolis, 1944, done by F. Brown. The test scores found a 31 per cent overlapping. (At very early ages, overlap always is greater because tests deal more with performance and with sensory-motor responses, and less with verbal skills). 5. A study by T. F. Rhoads and associates of white and Negro children at the age of three. This was a very detailed study, in which each of the subjects was clinically examined from birth until the time he was administered a psychological test. Socio-economic factors were reported to be generally equal for the entire group of subjects. The overlapping amounted to 30 per cent.