Fluidity of racial categories aside, the "biologification" of race in Brazil referred above would match contemporary concepts of race in the United States quite closely, though, if Brazilians are supposed to choose their race as one among, Asian and Indigenous apart, three IBGE's census categories. While assimilated Amerindians and people with very high quantities of Amerindian ancestry are usually grouped as caboclos, a subgroup of pardos which roughly translates as both mestizo and hillbilly, for those of lower quantity of Amerindian descent a higher European genetic contribution is expected to be grouped as a pardo. In several genetic tests, people with less than 60-65% of European descent and 5-10% of Amerindian descent usually cluster with Afro-Brazilians (as reported by the individuals), or 6.9% of the population, and those with about 45% or more of Subsaharan contribution most times do so (in average, Afro-Brazilian DNA was reported to be about 50% Subsaharan African, 37% European and 13% Amerindian).

What categories have an aspect of fluidity?