Complexity and social stratification likely don't appear out of "thin air", even though it is often characterized as such. Instead, ecological and social processes create environments conducive to their development. Compare and contrast ecological and/or social setting of Norte Chico and the Olmec. Using the models by Haas, Hayden and Hooper, discuss what you believe to be the likely processes that led to social stratification and differentiation in each case. Are these processes reversible? Why or why not? And if so, under what circumstances?