Looks like black Americans see themselves as having experienced more atrocities by the hands of the whites and think that that on it's own gave them another layor of identity. Some of them also reject being called "African American" and would rather be addressed as "black American". And that makes them look like they wanna separate themselves from their roots and act all, better. Some Africans also are not really big on Anti-racism and even hesitate on calling themselves black. Which is messy.