Final answer:
Elman Service identified four main levels of social organization in human societies: bands, tribes, chiefdoms, and states, correlating with their subsistence strategies and increasing in social complexity and centralization of power.
Step-by-step explanation:
The different levels of social organization in human societies identified by anthropologist Elman Service are bands, tribes, chiefdoms, and states. These forms of social organization correlate with the societies' subsistence strategies. Bands are small, egalitarian groups with no formal leadership, found among hunter-gatherers. Tribes consist of several extended families with informal leadership, often found in pastoralist and horticultural societies. Chiefdoms feature a centralized authority and are based on agriculture surpluses. States are the most complex form, with a centralized government, formal authority systems, and social stratification, often emerging from diverse modes of subsistence and regional trade.
These levels of social organization develop as part of an evolutionary sequence, where societies can evolve from one form to the next. The transition from bands to tribes to chiefdoms and finally to states suggests a scale of increasing complexity and centralization of power, from the completely egalitarian structures of small bands to the heavily stratified and bureaucratized entities of states.