"While disadvantageous-inequity aversion is nearly universal and a response that we share with other animals, advantageous-inequity aversion appears to be a conditioned response that develops at a later point in childhood"
Yes, this is the development from the formation of our ego-personality-identity construct, self-view, image of self, sense of self, shifting from a more self-concerned, self-focused, self-centered and self-considered perspective on one side of the spectrum/polarity, to progressively include the external world, and others, into our worlview and how we behave. It is a move from self without much concern for others, towards a cooperative, social, reciprocal causal-effect understanding of self & others together.
As you say, unfair systems of inequity will be recognized and people's actions will reciprocate a causal balance in the long-term to correct such systems. This is a corrective responsibility that each person is required to make, and as a whole to represent the way of living we all choose to accept as our way of life in a society. Once the exploitative measures are recognized and people choose to do something about it, then the socio-ecnomic survivability for those who have chosen the unfair route, will begin to crumble.
Good post. I also talk about morality and consciousness in my own work. Peace.