A study was made of differential perception and definition of race in the distinct cultures of Brazil, the U.S.A., and the North American Indian; and in two subcultural regions: the Intermountain West and the Pacific Coast. The data, except for Brazil, were gathered in a university context. The Brazil sample was 118; U.S.A, 136; and, for the North American Indian, 49. One instrument used to measure Interracial Sensitivity was of the projective, Thematic Apperception Test design. The other instrument measured Racial Definition. To prevent sensitizing the subject, the second instrument was always given after the first. There was no measurable difference found in both the perception and definition of race in different cultures and subcultures. Racial sensitivity was found to be not scalable. There were no significant effects associated with urbanization which had been thought to sharpen racial sensitivity and consciousness. This study suggests the emergence of some socially significant new trends in patterns of racial response. [Not available in hard copy due to marginal legibility of original document.] (JM)