Most encounters between police officers and blacks are predisposed to mutual hostility because both parties carry cultural knowledge, attitudes, and social awareness that can lead to conflict. Factors which complicate the experiences of police officers and urban residents include the history of internal migration patterns, the historical relationship between blacks and whites, the revolution of rising expectations, and the patterns of behavior dominant in the lower socioeconomic black subculture and the police occupational subculture. The concepts of subcultural behavior, culture shock, and culture fatigue can give officers the ability to make judgments which lead to few, rather than more, tensions and difficulties in dealing with black citizens. 35 notes