How cooperation drove the evolution of vocal production learning in hominins

Sabine Stoll, Carel van Schaik, Judith M Burkart, Konatsu Ono, Nikhil Phaniraj, Zitan Song, Balthasar Bickel

Language evolved uniquely in the hominin lineage. Critical to its evolution was the emergence of vocal production learning (VPL), the ability to acquire novel vocalizations. The mechanisms underlying VPL have been extensively studied across taxa and are convergent with hominins. However, the drivers of hominin VPL are still unknown. Reviewing the various functions of VPL across taxa, we propose that hominin VPL was selected for by the increased need for cooperation-induced communication in the new hunter-gatherer niche that formed after the move to the savanna at ca 2 Ma ago. The transition rests on two  processes: (1) the amplification of an inherited mechanism of vocal accommodation, in which individuals align acoustic features of their vocalizations to enhance affiliative bonds; and (2) the emergence of babbling, in which infants train interactive learning mechanisms. Our perspective opens new directions for research on language evolution, focusing on the communicative needs of hunter-gatherer cooperation.