I'd be curious to do a deep-dive comparison between northern and southern kingdoms and empires in the ancient world, to see if there's a pattern there that's consistent with this hypothesis.

If by "northern friends," you include the Nordic countries in Europe, I examine them in an upcoming article in this series.

But sure, civilizations didn't begin in the north. That's likely because those areas would have been harder to cultivate, given the lower level of technology. Also, the tropical areas are superficially more desirable. That's why everyone vacations in those areas.