I wasn't referring to climate change, etc. when I replied to the nice Danish fellow. I was mostly referring to his note regarding the sense of community and equality in Denmark.

My point is that cultural dissimilarity creates a lot of mistrust and frustration. If I don't have the same common goal as my neighbor, and we have a completely different style--our chances to be in conflict are a lot higher, and so my likeliness of wanting to help him out are much lower.

I'm from Israel, and even if you look just at the Jewish demography, the differences between the different groups, are huge -- even though we all speak Hebrew, part of the Jewish culture/religion in some way, etc. The life goals of a secular Jew in Tel-Aviv, could be almost the complete opposite of a religious Jew in Jerusalem -- you can imagine the conflict to be quite immense, and hence the sense of community greatly eliminated.