Monoethnocentric
(1) The belief that racial and ethnic labels are mutually exclusive (2) The tendency to identify ambiguously phenotyped individuals as one race and/or not recognize the existence of mixed individuals (3) The belief that culturally complex individuals should only identify with one culture (3) The prejudicial belief that individuals not identifying with only a single race or ethnicity are intrinsically more psychologically maladjusted.
"The media showed a disturbingly monoethnocentric bias in forcing Tiger Woods to publicly identify as one race even after discovering his multiracial background."