
The best explanation I've read of this is Tim Urban's "The Story of Us" series [1]. It builds up a model from individual behavior to societal behavior and how it's changed over the decades due to how online interactions have shifted behavior (both individual and societal).
I don't know whether it's the right or wrong model and explanation, but he lays it out very clearly.
I started "The Story of Us" [3], but haven't gone through all. I think it crossed the threshold of long-blog-post and became almost a book-in-a-blog.
[1] https://waitbutwhy.com/2014/10/religion-for-the-nonreligious...
