Aenima is the transition from proto-history to ancient history (when humans began to write).
This is the period when humans began creating symbols, numbers, basic measurements, and developing a greater sense of past and future. Humans are expanding their memory and gaining a longer sense of time.
They're learning better techniques for growing larger amounts of crops, making inventories of their crops and beginning to barter with other tribes. They are planning out there immediate futures better. Surviving longer.