I will share one observation. I noticed that people of similar views of the world in general, and on anything in particular, just is not "accidentally" agree with each other. If you look closely, it turns out that they had in common that is rarely random, namely - books.
The choice of books as a child - is the question determines the rest of our life. And often the books that became favorite, each page of which we know almost by heart - by these books were formed views.
I have to say about my experience. We had a quite similar list of books. And there were almost the same favorite books. I say "almost", because there is always an element of "distinction" leading off from the monotony towards to the possible and often quite fundamental dispute.
At friends do not necessarily share the same favorite books. But friends necessarily have a common language. Which gives only the reading of same books.
As for the dispute, it has long been known that it is possible only when you have more in common than differences. The dispute involves the presence of common paradigms, common language, common notions of good and evil. People who do not have anything in common, never will have any dispute, nor quarrel.
Therefore, we dispute with those who are similar to us.
Such a meeting - a great joy. Suddenly, we meet a man whose soul is running on our frequency. Who will hear when we're talking. And he understands.
It happens - our thoughts, our feelings - suddenly voiced a completely by unknown person. He says, as if reading our mind and heart.
This means we have a common language. The real, the first, which is more familiar to us. And this language does not always need words ...
