[girzel]

Sure, I don't think it's a silver-bullet explanation, just one that you hear frequently. I still think it holds water, to a certain extent -- the central plains have continually been the cradle and heart of Chinese civilization. And one of China's most culturally fruitful periods, Warring States, occurred when even the central plain was fragmented, which would seem to uphold the theory of the article.

I think spread out over enough time, these pervasive environmental factors do have a real influence. You could see the unity of the Roman Empire as being Europe's fluke, and the disunity of the Warring States as being China's.

But again, it's really all speculative.