Final answer:
Early human societies, like hunter-gatherers, were nomadic and exhibited social divisions, suggesting they were not truly isolated. As civilizations evolved, trade and cultural contact between societies increased, demonstrating interactions and interdependence within human groups. Anthropological evidence shows that cooperation is a natural part of human community, further disputing the notion of complete societal isolation.
Step-by-step explanation:
The idea that truly isolated human societies probably never existed can be understood by considering the nomadic nature of early human hunter-gatherer societies, who roamed in search of food and could not easily be controlled politically. Even in ancient times, the small communities of hunter-gatherers exhibited some level of social division and differentiation, suggesting a complexity in relationships that goes beyond strictly isolated groups. The archaeological record, alongside observations of contemporary hunter-gatherers, offers insights into early human societies, indicating that while societies may have been small and less complex than modern states, complete isolation is unlikely.
As societies evolved, interactions increased, particularly with the advent of agriculture and the formation of static communities. Trade, the exchange of ideas, and cultural diffusion began to occur, further negating the idea of absolute isolation. Moreover, the belief in wholly isolated societies conflicts with anthropological findings that even in stateless or small-scale communities, decision-making and cooperation exist without the need for formal leadership, suggesting a level of interaction and interdependence within these groups.