Don't you think your morality is not real and it's actually given by the society and not nature, it's not at?

all natural, just think of those cannibals living in jungle who eat other human beings, we who are living in civilized society will never think of doing such a thing and even if we did we would feel bad about it, but these cannibals have no such thoughts, is a sense of right and wrong absent in them, if morality is universal and something given by nature, why don't they feel bad about killing another human being and eating him ?