The thing about the modern world is that it's possible to compare two pieces of information from completely different places. This wasn't always possible: The speed information travelled from England to America was the same speed people travelled there. It is possible, as it wasn't before, to have a world empire, a top-down control system. Once upon a time we could only communicate with neighbours, and the world was bottom up, cellular automaton, emergent. Today there are only neighbours.
This has coloured the way we think. But what if it wasn't like that? What if there was cultural diversity not from any historical differences, but because it was impossible that uniformity could be maintained? If humans conquer the galaxy, that's what it'll be like. And we'll think differently, have different social ideas, different philosophies because of it.
Sometimes I think like this: Imagine a grid of people all standing just within shouting distance from each other, over the entire country. When a person hears a shout, they repeat it. How would that look, from above, seeing that ripple of noise moving around? How would information travel? How would it interact? This is closer to how the world really is, and we forget that.