I think we all start out as fundamentalists - but through philosophy and literature we move through further stages that imitate the history of thought. So that we seem to keep moving through stages. Here is an interesting bit from Bernard Lewis "The End of Modern History in the Middle East":

"Democracies may negotiate and compromise with other democracies. For religions this is much more difficult and, for fundamentalist religions, impossible." p. 22

Following Francis Fukuyama (and others), in order to have a successful democracy you need (enough) modern individuals - those who have moved beyond the stage of fundamentalism - or tribalism! - and for an individual to reach that stage (following Harold Bloom "Shakespeare and the Invention of the Human") you have to become like Hamlet in being able to self reflect. Interesting thesis since modern democracies arose only in conjunction with the literature and culture of the modern individual.

If our school system fails to raise enough modern individuals we slip back into tribalism ourselves.

I haven't finished Steven Pinker's book "The Better Angels of our Nature" but that would seem to lead to the idea that peace and propserity goes with the success of that sort of education as well.