The purpose of the study was to compare the performances of black and white urban high school students on a conventional measure of intelligence, the Lorge Thorndike vocabulary test and a culture specific test, the Black Intelligence Test of Cultural Homogeneity. In addition to determining whether or not there were race differences in performance on either or both tests, other objectives of the study were: to determine whether or not there were sex differences in performance; to determine whether or not there were grade level differences in performance; and, to determine whether whether or not there were interaction effects between, or among, race, sex and grade. Both tests were administered to 229 black and white, tenth and eleventh grade students in an inner city high school in an upper midwestern U.S. city. The main findings were as follows: black students scored significantly higher than white students on the Black Intelligence Test of Cultural Homogeneity while white students scored significantly higher than black students on the Lorge Thorndike vocabulary test. Older students scored higher than younger students on the Black Intelligence Test of Cultural Homogeneity. Sex interacted with race and grade indicated that race was the only independent variable which had a statistically significant effect on the Lorge Thorndike test. (Author/JM)