Whether laboratory studies adequately reflect real-life situations is not firmly established. But there is growing evidence, according to social scientists, that hidden biases are related to discriminatory behavior in a wide range of human interactions, from hiring and promotions to choices of housing and schools.

In the case of police, bias may affect split-second, life-or-death decisions. Shootings of black men incorrectly thought to be holding guns — an immigrant in New York, a cop in Rhode Island — brought this issue into the public debate.

It is possible unconscious prejudices and stereotypes may also affect court jury deliberations and other daily tasks requiring judgments of human character.

People who argue that prejudice is not a big problem today are, ironically, demonstrating the problem of unconscious prejudice. Because these prejudices are outside our awareness, they can indeed be denied.