Excellent observation, Susan! Here is the last paragraph for the lazy ones:

Most damage done by oppression is done by its internalized form, in which the victims continue to oppress themselves, oppress each other within the group of the oppressed, and, as a group, attempt to oppress other groups and the members of these other groups who are oppressed in a similar way to the way their group is oppressed. The person outside a particular oppression can be powerfully effective against the internalized form of the oppression.