Final answer:
Anthropologist Elman Service proposed the classifications of bands, tribes, chiefdoms, and states based on subsistence patterns and political systems.
Step-by-step explanation:
The classifications of bands, tribes, chiefdoms, and states were developed by anthropologist Elman Service in the 1960s and 1970s. He categorized social organizations according to their modes of subsistence and political systems, where bands were associated with gathering and hunting; tribes with horticulture; chiefdoms with agricultural surplus; and states with a combination of subsistence strategies, military conquest, and regional trade. This framework helps in understanding the evolutionary sequence of societies and how integrative and conflict pressures have led to their progression from simpler to more complex forms.
Before 1400, the world consisted of a diverse mix of social organizations, from empires and kingdoms to bands and tribes. Over time, these societies evolved, influenced by various pressures such as population growth, social stratification, militaristic threats, and opportunities in regional trade, leading to the creation of modern nation-states. Service's theory offers a view on how societies transformed through time, migrating from loosely organized bands to highly structured and centralized states.