What reason does warren give for making the claim that comparing tangible factors is not enough to evaluate segregation

The real impact of racial segregation is emotional damage to minority students

Explanation:    

If it is true that chronic stress disorder most of the time has negative side effects on all people, it is also true that the specific pshycho-social and contextual factors can affect more African-Americans,  in particular because of  the widespread and persistent exposure to racism and discrimination that they are victims of.

This situation creates an additional everyday stressor for African-Americans and obviously it makes them more likely to suffer not only stress but also different health conditions that can be triggered because of it. In addition, emotional damage is another factor that affects normal and free personality development.

i believe it is "he will always remain extremely timid" if its wrong sorry

c. barbarians with unexpected intelligence