Just because people barter or keep scores, it doesn't mean they can't do other things, like be nice or give gifts occasionally.

Honestly, to cut the discussion short: do you have kids? I have two kids. Maybe I am doing something wrong, but they are really not all that naturally generous and giving to each other. Must be the toxic capitalist environment they grew up in? How can I activate their socialist genes and make them want to share all their toys with each other?