I have wondered if one reason sharing is so challenging is culture, not genetics.
I remember reading an article about a women and a few friends who moved out of a city to the country to start an intentional community. The purpose was to get away from she called a competitive and isolating nature of city life.
What she discovered was her group recreated the same problems they experienced in the city within their group. This was quite shocking to her.
This lead her to conclude that successful sharing is not just changing the physical location. It involves changing how to do things and how we relate to each other and the world.
I remember reading about a tribe that hunted dear. When the hunter returned, the dear parts were shared with tribe. There was no need for a big meeting to figure what to do. They had developed norms established around sharing the dear over years, generations, around who got which parts and how many. Those who grew up in the tribe, did not need to figure out how to share the dear. They learned how to share thru learning the tribe culture, tribe's norms.
I wonder if in our current culture, we have developed social norms that cause sharing to be almost impossible. If so, which norms do we change, so we can share more easily ?