Simulating the coevolution of language and long-term memory

Memory is fundamental to social activities such as language communications, yet it remains unclear how memory capacity and language use influence each other during language evolution, especially the early stage of language origin. Here, we proposed an evolutionary framework to address this issue. It assumed a genetic transmission of memory capacity and integrated natural and cultural selections that respectively affected the choices of parents for reproducing offspring and teaching these offspring. Simulation results obtained under this framework and relevant statistical analyses collectively traced a coevolution of language and capacity of individual long-term memory for storing acquired linguistic knowledge during the origin of a communal language in a multi-individual population. In line with the coevolutionary theory of language and related cognitive competences, this simulation study demonstrated that culturally-constituted aspects (communicative success) could drive the natural selection of predisposed cognitive features (long-term memory capacity), thus showing that language resulted from biological evolution, individual learning, and socio-cultural transmissions.