6.1.5 Hominin Material Culture

Evidence from the material culture of hominins such as Homo habilis and Homo erectus is also used to speculate about the emergence of human language. Early hominins developed stone tool technologies and created stunning works of art. The production and use of such tools and artwork must have required a complex set of social and cognitive abilities. Those same types of social and cognitive skills are important to human language. It is possible that language emerged as part of a whole complex of material culture.

Archaeological evidence and linguistic theory come together in a model suggesting that the invention of tools by early hominins was linked to the invention of language. Some linguistic theorists suggest that the evolutionary changes in brain structure that allowed for the development of tool use also support the emergence of language. Furthermore, the innovations of tools and language are entwined in a reciprocal relationship; evolutionary pressure to develop tools stimulated the development of language, and the development of language facilitated increasingly complex tool making and tool use.

There are two theories to explain the connections between advances in tool use and language. The first rests on the assumption that tool making requires a considerable degree of cognitive planning. You cannot make a useful tool by just picking up a rock and randomly chipping away at it. Hominins like Homo habilis and Homo erectus must have known just what kind of rocks would work as base and chipper and how to execute a set of precise chips in a certain sequence to achieve a sharp blade without breaking the core. The mental processes important to this sort of planning are hypothesized to have also enabled hominins to do the sort of quick planning involved in the production of complex speech (Tallerman and Gibson 2011).

A second theory linking tool use and language emphasizes the importance of imitation in passing along the complex set of skills involved in tool making. Neuroscientist Michael Arbib suggests that the ability to imitate may have generated the first gestural language among hominins (2011). And he has developed a model to describe how imitation and tool making may have evolved together over time. About 2.5 million years ago, Homo habilis began making basic stone choppers, cores with flakes removed, used for butchering carcasses. Such choppers are called Oldowan tools, named after the site in Olduvai Gorge in Tanzania where they were first found. Arbib has theorized that the production of Oldowan tools required the ability for hominins to imitate each other’s actions. Simple imitation would make it possible for a learner to reproduce the actions of an accomplished tool maker through observation and mimicry. This ability to imitate is biologically rooted in the system of mirror neurons discussed earlier. As hominin brains acquired the ability of simple imitation involved in tool production, they might also become capable of the kind of gestural communication we see in apes today—not language, but a precursor to it. Investigate this diagram for more about the evolution of language.

The array of action-oriented mirror neurons, tool innovation, and language all progressed together in hominin evolution. As tool technology developed, Homo erectus began making distinctive pear-shaped hand axes about 1.6 million years ago. A more intricate form of imitation would have been necessary to teach this sort of tool making to others, corresponding to the emergence of protolanguage. This protolanguage might have been a set of simple one-word utterances corresponding to concepts such as “yes,” “no,” “here,” or “there.”

We don’t have any hominin brains to examine, but remember that in the human brain, the system of mirror neurons is assumed to be situated near Broca’s area, which is associated with human speech. So very likely, protolanguage emerged in the same part of the brain as the ability to imitate. The explosion of innovations in tool making over the past 100,000 years is linked to the emergence of complex human language. While the development of mirror neurons and the ability to learn tool making required biological changes to the brain, Arbib argues that the last step, the emergence of language, was purely cultural.