I don’t think scale is the issue, or at least not the only issue. I think it’s too many people not knowing each other, a lack of homogeneity in belief systems. But I do have a solution - universal military service for 2 years before entering college. You don’t have to fight anybody, but learn how to use a gun if you’re going to insist on owning one, meet and understand your neighbours and fellow citizens, tour the country, spend some time in cities as well as rural areas, learn a trade. In return you get universal healthcare for life and a vocation. Go to university afterwards if you feel like it. Start it as voluntary and grow from there.

Thanks for the excellent post and for thinking about this. Keeping organizations small is definitely a way to avoid this sort of problem.