Authors:

I have touched here on a problem that is masked if one speaks of racism. And that is the fact that the major differences between the established and outsiders group, which create tension and irritation, is not the form of the face or the skin color but the form of behavior: something learned. The form of behavior and feeling, of sentiment, is different in the immigrant groups from that of the established groups, and that may give rise to an enormous irritation.

Source: quod.lib.umich.edu
I have touched here on a problem that is masked if one speaks of racism. And that is the fact that the major differences between the established and outsiders group, which create tension and irritation, is not the form