In systems too large for a single group, there are layers of decision-making: the nomads of the Sahel, for example, used to have overlapping informal authorities up and down the Niger river.

• 在一个对于单一群体来说非常大的系统里，有着许多决策层：例如萨赫勒的游牧民族，过去有着许多互相重叠的非正式权威遍布于尼日尔河上上下下。