Some thoughts stemming from recent reading submitted for critique if anyone were so inclined:
Writing reconfigures the relationship of the individual vis a vis culture; it introduces a fulcrum by which an individual may extricate themselves (to significant degree, if never entirely) from their culture. With the introduction of writing, knowledge, memory, communication, and with these the self, are situated on a trajectory that runs from contextualized to abstracted, or from associated to alienated.
The connection of writing to memory is especially important in this regard. The path to robust individualism runs through the democratization of the means of memory production. When writing enters into primary oral culture it typically does so in the service of institutions and bureaucracies. So it is the memory of the tribe, group, or nation that is generated and memorialized. The average individual still subsumes their story within that of the larger body. As the means of writing (and later photography, etc.) are democratized, the individual is able to create and sustain personal rather than collective memories and thus construct and maintain an identity independently of the group.