Social capital is inversely proportionate to racial diversity. So Los Angeles, the most diverse big city in the United States, has the lack of cooperation among its citizens.
I was watching this 2012 documentary, The Summit, about climbing accidents on K2 that took 11 lives in one day. Much of the disaster was apparently caused by the differences in competence among the various groups (all divided up on ethnic lines).
I’m not an expert on mountain climbing, but it seemed that next to the native sherpas, the most proficient group were the Northern Europeans and other groups tried to sponge off them and appeal to them for rescue from their own incompetence. It seemed like the Korean group didn’t know what they were doing, and their bumbling around cost their own lives as well as the lives of outsiders.
I was struck by how the different ethnic groups in the movie had radically different capabilities, ethics, solidarity, altruism and other values essential to creating a good and prosperous community.