I don't see this as nature as much as engineering and programming. we have essentially forced our nature into submission through disconnection from a community. As social animals, disconnection fro community is unnatural.

I would posit that it is how our nature reacts to not being in our natural setting. When we work together we work from a stand point that we know we will have each others backs. When you don't have that support you're probably more inclined to hoard what you have in case of bad times and grab as much as you can, when you can, to add to the stockpile. If you think of someone who is fending for themselves it makes sense. What we currently have is instead of being physically alone, we are surrounded by people we don't know or trust. On here they are faceless too. I wonder if the greedy ones even acknowledge other people beyond their grab for riches.