I really like this description of a 'win-win' situation. It seems that many times people get hung up on having their side win. The bit I like is: 'Each person senses that they got the best they could given the needs of the group and other people within it. “This is the best I can achieve for myself in this community, and best you can achieve.” ' It seems like your major idea is that people are not 'supposed' to agree. This seems at variance with what most people hope will happen in a relationship. However, I think the fact is that most couples do not agree on many things. So, perhaps this is the reality. It's not the rose-tinted glasses that people might like, but it can make it possible to live together peaceably.