Explain how understanding the past can lead to a change in racism

Historical knowledge predicted racism perception for both African Americans and European Americans, the researchers found, and overall, the African-American students were better at identifying historically true events. African-American students who reported greater relevance of racial identity also perceived more racism, while European-American students who placed greater importance on their racial identity saw less racism, especially on a systemic level, the researchers said.

The results suggest that knowledge of historically documented racism partially may help explain the relationship between someone's race and their perceptions of racism.

Where is the map? explain the choices?