Writing
The invention of the first writing systems is roughly contemporary with the beginning of the Bronze Age of the late 4th millennium BC. The Sumerian archaic cuneiform script and the Egyptian hieroglyphs are generally considered the earliest writing systems, both emerging out of their ancestral proto-literate symbol systems from 3400 to 3200 BC with earliest coherent texts from about 2600 BC. It is generally agreed that Sumerian writing was an independent invention; however, it is debated whether Egyptian writing was developed completely independently of Sumerian, or was a case of cultural diffusion.
Proto-Elamite
A few Proto-Elamite signs seem either to be loans from the slightly older proto-cuneiform (Late Uruk) tablets of Mesopotamia, or perhaps more likely, to share a common origin. Whereas proto-cuneiform is written in visual hierarchies, Proto-Elamite is written in an in-line style: numerical signs follow the objects they count; some non-numerical signs are 'images' of the objects they represent, although the majority are entirely abstract.