Although many aspects of human cognition are likely to be “spandrels” passively affiliated with the primary impetus for hominid brain expansion during the Plio-Pleistocene, that expansion was most likely generated and maintained not by “housekeeping” functions but by improved capacities of reproductive success, especially survivorship.
Behavioral and Brain Sciences
Lovejoy, C. Owen (2001). Hominid Brain Expansion and Reproductive Success. Behavioral and Brain Sciences 24(2) 290-290. doi: 10.1017/S0140525X01343959. Retrieved from https://oaks.kent.edu/anthpubs/53