Scholars are not completely sure which society developed writing first.  This is largely because each of the early writing societies don't leave us any explanation about how it was doen in the context of a particular time.  The Sumerians, in one of their great epic poems tell us that a messenger from their king tried to deliver a message to another king but upon arrival was too exhausted to be able to speak. The next time that the Sumerian king needed to send a message, he patted down some damp clay and wrote the words of his message on the clay, baked it to make a tablet, and asked the messenger to take it along to deliver to the neighboring monarch.

"Before that time writing on clay had not yet existed,
But now, as the sun rose, so it was!
The king of Kullaba [Uruk, in Mesopotamia] had set words on a tablet, so it was!"

Of course this story is not believable in its details - the recipient would not have been able to read it!  But it is clear that the Sumerians came to understand that writing was useful for storing information and transmitting information outside of immediate human memory and over time and over space.  We are now pretty sure that this "invention" took place between 3,300 and 3,200 BCE, and was one of the major causes for the development of civilization as well as, in a sense, a result.  Let's remember the dates associated with Catal Hoyuk, perhaps the first agricultural village.  This means that it took humans, once having established agricultural communities and villages 4,000 years to develop writing!

Archeologists have found thousands of clay tablets associated with sites from that 100-year period in Iraq - though of course they have not recently been working in the field there!.  These tablets have picture symbols on them - not yet cuneiform script as discussed in the textbook - that appear to represent names of people, places and objects important to trade and ruling.  Scholars who study the growth of language (linguists) beliee that it took at least 500 years before this "writing" came to represent spoken language.

But as you will discover as you work on Project 1 - Mesopotamia - which will be due at the end of unit 6 - we have found a great many more types of sources besides writing which allow us to understand ancient history.  So now we more likely use the term pre-literate rather than pre-historic to describe such peoples and societies.