An interesting problem concerning the development of writing systems, is the following: where had they first appeared? Probably, writing systems developed independently in at least three places, Egypt , Mesopotamia and Harappa . In places where an agricultural civilization flourished, the passage from the use of symbols to a true writing system was early accomplished. It means that, at certain period in some densely populated area, signs and symbols were eventually used to create a writing system, the more complex society requiring an increase in recording and communication media.
On Harappa culture see http://www.mongabay.com/reference/country_studies/india/all.html
The earliest signs of human activities in India go back to the Palaeolithic Age, roughly between 400,000 and 200,000 B.C. Stone objects and cave paintings from this period have been discovered in many parts of the South Asia . Evidence of domestication of animals, agriculture, permanent village settlements, and wheel-turned pottery, dating from the middle of the sixth millennium B.C., has been found in Sindh and Baluchistan, (both in Pakistan) Indus River valley in Punjab and Sindh.
The remains of two major cities - Mohenjo-daro and Harappa - reveal remarkable urban planning, systems of water supply and drainage. Excavations at these sites and later archaeological digs at about seventy other locations in India and Pakistan provide the knowledge of what is now generally known as the Harappan culture (2500-1600 B.C.).
The major cities contained a few large buildings including a citadel, a large bath, flat-roofed brick houses, fortified administrative or religious centers having meeting halls and granaries. Essentially a city culture, Harappa civilization flourished because it was supported by a solid agricultural production and by the commerce, which included trade with Sumer in Mesopotamia . The people made tools and weapons from copper and bronze but not iron. Cotton was woven and dyed for clothing. Wheat, rice, and several vegetables and fruits were cultivated. A number of animals, including the humped bull, were domesticated. The scholars consider the Harappan culture as conservative, because it seems that it remained relatively unchanged for centuries: for instance, when the villages were rebuilt after flooding, the new constructions closely followed the previous ones. Stability seems then to have been one of the features of this civilization, but it is not yet clear who had the power, whether an aristocracy of priests or the community of traders.
Interesting artifacts of Harappa are steatite seals. These small, flat, squared objects with human or animal motifs provide a picture of the Harappan life. They also have inscriptions generally thought to be in the Harappan script, which has eluded the scholarly attempts at deciphering it. There is a large debate whether these signs represent numbers or are an alphabet. If there is an Harappan alphabet is proto-Dravidian or proto-Sanskrit?
A possible reasons for the decline of civilization of Harappa was the i nvasions from central and western Asia, destroyers of Harappan cities. Other causes were several recurrent floods, earthquakes, the increases of soil salinity and desertification.
Let me compare in the following figures, a small terracotta elephant head from Harappa and a representation of Ganesha (Museo Arti Orientali, Torino), and a small statue form Mohenjo-Daro
For more references on the problem of Harappa writing system, see
“Icons and signs for the ancient Harappa ”, http://cogprints.org/6179/
