Blacks have been found to score lower on tests of verbal aptitude when tested by whites than when tested by blacks. This best illustrates the impact of

The correct answer is - stereotype threat.

Explanation:

Stereotype threat is a conditional or temporally predicting in which individuals are likely to feel or experience themselves to be a risk of conforming to stereotype about their social groups.

In this case blacks, academic performance shows the impact of stereotype threat which is allegedly a key factor to racial for long period in academic performance.

Thus, the correct answer is - stereotype threat.