The mimetic theory of development was the central pillar in Donald's three-part model of symbolic cognition proposed in his 1991 book Origins of the Modern Mind.
Technology-supported culture: Finally, the cognitive ecology dominated by ephemeral face-to-face communication has changed for most of us as a result of the external memory-store that reading and writing permit.
"Donald argues for a four-phase process of development in the hominid brain in memory and social-cognitive systems that left humans with the cognitive infrastructure that we still retain today.
Donald's theory of the evolution of the human mind with mimesis at the core of things is very dependent on a lineage that is highly period-based, likely as a means to help explain some of the contradictory gaps in the archaeological record, where tool use, cultural artifacts, mastery of fire, and brain size (based on skulls that have been found) seem to either conflict, or have missing steps in their development.
The existence of these neurons should likely trace their roots back closer to a common ancestor with modern primates, the only other species noted with mirror neurons, and some of the intentional and mimetic capabilities that Donald attributes to the evolution of the mimetic mind in Homo Erectus were likely around much earlier in some simplified form, perhaps as the foundation of the rigid social hierarchies that our primate cousins are known for.
Thus, the divergence of cognitive capacities between humans and lower hominids may not be due so much to mimetic culture as it is due to some mutation that increased that plasticity in our brains around the time of Homo Erectus, perhaps in part related to the mastery of fire during this period, which would have allowed for cooking and the ability to ingest enough quality nutrition to give our brains the resources to make its final push into its modern stage of development.
This increase in plasticity would certainly be a mutation or upgrade supported by natural selection; a brain that can learn faster, more efficiently, and calibrate itself more properly to the needs of body and mind in the environment provides an absolutely massive leg-up on the competition.