Correspondence between genetic clusters in a population (such as the current US population) and self-identified race or ethnic groups does not mean that such a cluster (or group) corresponds to only one ethnic group. African Americans have an estimated 20–25-percent European genetic admixture; Hispanics have European, Native American and African ancestry. In Brazil there has been extensive admixture between Europeans, Amerindians and Africans. As a result, skin color differences within the population are not gradual, and there are relatively weak associations between self-reported race and African ancestry. Ethnoracial self- classification in Brazilians is certainly not random with respect to genome individual ancestry, but the strength of the association between the phenotype and median proportion of African ancestry varies largely across population.