Early Indus River valley civilization appears to have been quite advanced; perhaps more so than other contemporary civilizations. The society was apparently quite wealthy with a notable degree of social stratification. Evidence indicates that the society utilized standard units of measurement, even down to bricks used in construction. There were two major cities with city walls, a citadel and a large granary. It appears that taxes were collected in the form of grain and redistributed where needed. Both cities had marketplaces, a temple, and very large residential areas. Both cities were laid out on a carefully constructed grid; and contained large public pools with dressing rooms attached. While it is apparent that most people lived in one room homes in buildings similar to a barracks there were large homes consisting of two and three levels and twelve or more rooms. these larger homes had running water and flush toilets that emptied into a central sewer system. Little is known of their religious system, although it is known that they traded extensively throughout the area, possibly as far as Mesopotamia. There is some argument that their religion was based on a god of fertility, similar to the Mesopotamian gods of Baal and Astarte. It is known that the society was largely agricultural, and appears to be the first to domesticate chickens.
Information on the civilization is somewhat sparse, as most of the surviving artifacts are under water. Additionally, their language, which appeared to be phonetic in nature and had over four hundred symbols, has not yet been deciphered.
The society went into decline c. 1900 B.C.E. and had disappeared by 1500 B.C.E. Evidence suggests that the people cleared large areas of forest to increase the amount of arable land. This deforestation resulted in reduced rainfall and erosion of the topsoil, which left the area poorly suited for agriculture even to this day.
The artifacts discovered in these cities suggest a sophisticated and technologically advanced urban culture. The concept of urban planning is also widely evident. There is also the existence of the first urban sanitation systems in the world. the sewerage and drainage system found in the each and every city of Indus Valley comes across as even more efficient than those in some areas of Pakistan and India today. Dockyards, granaries, warehouses, brick platforms and protective walls have been found in almost all the cities of the Indus Valley Civilization. The evidence suggests that most city dwellers were traders or artisans, who lived with others belonging to the same occupation in well-defined neighborhoods. Social equality seems to be widely prevalent in the cities of Indus Valley, though there are some houses that are bigger than the others.
The people of Indus Valley are believed to be amongst the first to develop a system of uniform weights and measures. Their smallest division was approximately 1.704 mm. Decimal division of measurement was used for all practical purposes. The brick weights were in a perfect ratio of 4:2:1. The numerous inventions of the Indus River Valley Civilization include an instrument used for measuring whole sections of the horizon and the tidal dock. The people of Harappa evolved new techniques in metallurgy and produced copper, bronze, lead and tin. They also had the knowledge of proto-dentistry and the touchstone technique of gold testing.
The change in climatic conditions, which was a cause of the increasing spread of desert conditions also contributed to the final end to one of the greatest ancient civilizations.