A new body of research argues that our ability to speak languages evolved from our hominin ancestors’ ability to produce complex tools. Accorsing to a study published in the journal Philosophical Transactions of the Royal Society, biologist Oren Kolodny argues that the process of passing toolmaking skills to kin caused early humans to develop the capacity for language.
Kolodny and his co-author, Shimon Edelman, a professor of psychology at Cornell University, theorize that the emergence of language was predicated on our ancestors’ ability to perform sequence-dependent processes, which included the production of complex tools. Their arguments are further bolstered by experiments conducted at Emory University by anthropologist Dietrich Stout. Stout taught hundreds of students how to make Acheulean-era tools (tools created during the middle Paleolithic period), while tracking their brain activity during the learning process, describes Ben James for The Atlantic. Stout discovered that the neural connectivity in his students’ brains increased as they gained competence in flintknapping. The research suggests that producing complex tools precipitated an increase in the brain size and evolution of hominins.
Still, the complexity of the languages spoken today didn’t happen overnight, Kolodny explains. “Every evolutionary process, including the evolution of language, has to be incremental and composed of small steps, each of which independently needs to be beneficial.” He adds that teaching was a crucial part of the process—by teaching close relatives how to make complex tools, hominins arrived at ever more specialized niches, with the advantage going to those individuals adept at toolmaking and communication.
Kolodny further argues that our ape relatives didn’t follow the same path because they don’t have the communication system coupled to “temporal sequencing structural capabilities.” Essentially, the neural networks required for complex, hierarchical, sequence-dependent tool production were re-purposed by our brain’s communicative apparatus and used for language, explains James. The same process that allowed complex, step-by-step tool-making, provided the basis for complex language requiring word order and sentence structure.