According to Guns, Germs, and Steel, what caused the Chinese to develop into a society with a hierarchical structure?

Diamond argues that hierarchical societies in all areas
come about because of agriculture.  He does say that agriculture and complex societies
sort of help one another develop and so it is hard to determine what the causal
relationship is.  However, societies with intensive agriculture are essentially always
hierarchical.

According to Diamond, agriculture makes it
possible for a society to have a high population density.  When many people live
together in close proximity, there is a need for a strong government.  If there is not a
strong government, the people (who have no kinship or friendship relations with one
another) will come into conflict all the time as the Fayu of New Guinea
do. 

With agriculture, then, comes the need for a strong
central government.  When there is such a government, society inevitably becomes
hierarchical because those in the government or those near to them come to have much
more power and wealth than those who are not. 

In addition,
hierarchy comes about because intensive agriculture frees up many people to do work
other than food production.  These people become merchants and artisans and even
bankers.  When this happens, hierarchy is much more possible because there is inequality
of wealth.

In short then, China, like all other societies,
became hierarchical because it had a dense, sedentary population made possible by
farming.