Reminding someone of a bad stereotype about their group can tank their test score

In a 1995 study, Claude Steele and Joshua Aronson found Black students performed significantly worse on a verbal test when it was framed as diagnostic of intellectual ability, compared to when the identical test was framed as a non-diagnostic lab exercise. The anxiety of confirming a stereotype, not any real ability gap, drove the drop.

— Claude M. Steele, Joshua Aronson, Stereotype Threat and the Intellectual Test Performance of African Americans — Journal of Personality and Social Psychology, 1995