Dr. Elman Service defined in 1962 the following levels of political complexity:
|Tribe||Hypothetically, a new tribe could develop when an individual took his family beyond the tribal area. Presumably, tribal names were derived from an ancestor deemed seminal to the tribe's formation. For example, Israelites deemed Israel (aka Jacob) crucial to their origins.|
|States||Characterized by a unified ideology, aka kingdoms or empires. Early State Modules (ESMs) presume that territory can only be ruled as well as it can be communicated with, and that pre-modern transportation was on foot.|
|Empire||An empire is a super-state that unifies a heterogeneous population under a common ideology.|
|Balkanization||Breaking up of a region into smaller territories, such as Czechoslovakia → Czech and Slovak.|
|Urbanization||Defined by: dramatic increase in population; fortifications; public buildings; and presence of a specialized bureaucracy.|
|Middle ground||A region where disparate people and cultures coexist.|
Brinkley. Unfinished Nation.