During this period society consisted of small groups and developed language, rituals, and used basic tools made of stone. The Neolithic Revolution, a term given the adoption of agriculture, transformed economic, political, and social organization. Its beginning can be found in the Middle East as early as 10,000 B.C.E. The use of agriculture gradually spread or was adopted independently in centers, including parts of India, North Africa, America and Europe.
It was not until about 3500 B.C.E. that the changes brought about by the Neolithic revolution brought about the development of early complex societies. Locations situated close to fertile river banks suited the development early complex societies because their economic production was based upon agriculture. Rivers were also used for cleansing and drinking as modern reticulation did not exist. Irrigation methods and calendars were developed to advance agricultural efficiency. Later, boats were constructed and used for transportation and trade. As the societies grew denser some of the other technological advances introduced were the potter's wheel, wheeled vehicles, improved shipbuilding allowing seafaring ships, and bronze tools.
The four great river valleys commonly recognised as forming the basis of early civilizations are the Tigris and Euphrates river valley in Mesopotamia, the Indus River Valley in India, the Nile River valley in Africa, and the Huang He River valley in China (Stearns, Adas Et al.)
Technology and the reorganisation of societal structures increased the economic viability of the now sedentary communities causing population sizes to increase dramatically. As the populations had vested interests in their land, ownership of property became more important which lead to increasingly complex societies where specialization, economic, political, and religious functions flourished.
The increases in economic production also promoted migration and trade, which furthered the diffusion of the technologies and intellectual capital necessary for the spread of early social complexity. Horse domestication ( +- 4000 B.C.E.) and bronze metallurgy played a pivotal role in this and influenced the development of societies from China to Egypt.
Advances in transportation technologies between approximately 3500 and 2000 B.C.E., such as "wheeled carts and wagons appeared in Mesopotamia" (Bentley 760), the construction of seaworthy sailing vessels by the Mesopotamians and Egyptians meant that although the population of the early complex society were sedentary, they did not develop exclusively in isolation. According to Bentley, "Mesopotamians and Egyptians traded with each other at least by 3500 B.C.E" (Bentley 760). The theory that the ideas and technology necessary for the formation of complex societies spreads through migration and trade is called the cultural diffusionism. The Olmec society in the Americas (1400 BCE to about 400 BCE) is a notable exception as in terms of this theory cultural diffusionism could not have been the sole driving force for the spread of complex societies.
Middle Eastern complex societies began in about 3500 B.C.E. with the Mesopotamians and continued with the Sumerians. In around 1800 B.C.E., the Babylonian Empire came to supremacy uniting all