How did it all get started? A comparative approach to language evolution
Comparative research in animal communication has revealed that many elements of language can be found in other species, but also how human language is nevertheless unique compared to the communication systems of other animals. Moreover, we increasingly understand how co-evolutionary feedback processes may have led to fully-fledged language once an initial threshold of becoming more communicative was passed. What is still poorly understood, however, is why this initial step occurred: Why was it our ancestors, rather than any other ape species, to take this evolutionary trajectory that would eventually lead to language? In this talk, I will explore the role of cooperative breeding, i.e. the systematic reliance of mothers on other group members to successfully raise offspring. Cooperative breeding has convergently evolved in humans and callitrichid monkeys, but is absent in other primates, most notably in all other apes. The core argument is that this breeding system sets the stage for increased interdependence and cooperativeness. Implemented in a great-ape like cognitive system - as the one of our ancestors – this likely had the potential to lift communicative motivation above the necessary threshold to allow language to evolve. I will use comparative and developmental data to exemplify this idea, and end by comparing it to alternative approaches that aim at explaining the early beginnings of language evolution.