This paper reports findings from a 1976 study of the causes of racial residential segregation in the Detroit metropolis. One of the reasons for the persistence of high levels of segregation is white ignorance of the changing values of other whites. If all whites— especially real estate dealers and lenders—recognized the willingness of most whites to accept black neighbors, to remain in racially mixed areas and even to consider purchasing homes in neighborhoods which have black residents, the pattern of whites fleeing when blacks enter their neighborhood might be altered. Blacks overwhelmingly prefer mixed neighborhoods but are somewhat reluctant to move into a neighborhood where they would be the only black family because they fear the hostile reactions of whites. Blacks may also be ignorant of the changing racial attitudes of whites and may overestimate the difficulties which would arise if they entered a white neighborhood.