one-drop rule

American  

[wuhn-drop rool] / ˈwʌnˈdrɒp ˌrul /

noun

1. U.S. History. a social classification, codified in law in some states during the 20th century, that identifies biracial or multiracial individuals as Black if they have any known Black African ancestry, even from a Black ancestor many generations removed.

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Etymology

Origin of one-drop rule

First recorded in 1920–25 (as one-drop law ); from the ideology that “one drop” of Black African blood made a person Black

Example Sentences

In seeking a basis for race-based organizing that forged a path between the absurd “one-drop rule” and the false promises of cultural essentialism, Du Bois had distilled centuries of racist pseudoscience, philosophy and law down to an image of the quotidian humiliation of a railway car.

From New York Times

“I think it goes to show you that even though we might in some ways celebrate being of mixed race, we still rely on what we call the rule of hypodescent, a.k.a. the one-drop rule — which is that if you are any partial ancestry that is non-European, you are Black, Latino, Asian, etc.,” she said.

From Los Angeles Times

“In middle age he learned that according to the one-drop rule of blackness, he was not white.”

From New York Times

And there are big differences in racial definitions across countries: in the United States, thanks to the so-called one-drop rule, a person with any Black heritage has historically been categorized as Black; in Brazil, an individual is not “Black” if he or she has any European ancestry.

From Scientific American

To grasp the full measure of Stella’s position, we must consider the concept of hypodescent, colloquially known as the “one-drop rule.”

From New York Times