There are plenty of studies that show that underrepresented minorities are, in fact, treated differently. Did your African-American classmates affirmatively tel

There are plenty of studies that show that underrepresented minorities are, in fact, treated differently. Did your African-American classmates affirmatively tell you that they didn't feel like they were treated differently, or was that your own inference? (I notice you qualified that they were never treated differently "in class".) And contrary to your implication, people don't have to be "racist" to treat people differently. It may just be unfamiliarity, but the net effect is still to give those subject to it a feeling of not belonging. Everyone has to put the work in. Maybe. But the amount of work needed to prove that you are "one of the team" is certainly not the same for everyone, no matter how much you want that to be the case.