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First conversations may have been about tools

Evolving language The first verbal conversations likely occurred between 2.5 and 1.8 million years ago and were about tool-making, a new study suggests.

The study, published in the journal Nature Communications, presents evidence that stone tool-making helped drive the evolution of language and teaching among prehistoric human ancestors in the African savanna.

"We suggest that the use of tools drove the evolution of language, and it seems likely that 'words' for things other than current emotional states would have been very useful for learning to knap," says lead author Thomas Morgan.

"The use of sounds or gestures for non-emotional concepts such as 'yes,' 'no,' 'here,' 'there,' 'good' and 'bad' would likely have been really useful," adds Morgan, who is a postdoctoral researcher in psychology at the University of California at Berkeley.

Morgan, University of Liverpool archaeologist Natalie Uomini, and their team conducted a series of experiments in teaching contemporary humans the art of 'Oldowan stone knapping'.

Oldowan refers to the oldest known stone cutting tools, which were likely made by Homo habilis (aka 'The Handy Man') and possibly also Homo rudolfensis, Australopithecus garhi and Paranthropus boisei.

The earliest known Oldowan tools date to 2.5 million years ago. They consist of butchering 'flakes' created by hammering a hard rock against certain volcanic or glassy rocks, like basalt or flint. The tools remained largely unchanged until 1.8 million years ago, when more sophisticated Acheulean hand-axes and cleavers marked the next generation of stone tool tech.

In testing five different ways to convey Oldowan stone-knapping skills to more than 180 college students, the researchers found that the demonstration using spoken communication, versus imitation, non-verbal presentation or gestures, yielded the highest volume and quality of flakes in the shortest amount of time and with the least waste.

Morgan suspects that other tasks, such as hunting and gathering, also could have been involved in the development of language and teaching skills, but probably not to the same degree as tool-making.

Language evolution

Since language has likely been around for at least two million years, there is little doubt that other human-like species, such as Neanderthals, did a lot of talking.

"Language was certainly already present before the Neanderthals and our ancestors split," says Uomini.

"The Neanderthals had some of the most complex stone tools ever made, which are also the most difficult for modern day knappers to replicate. That's why we think that their communication and teaching system must have been sophisticated enough to transmit the subtle and long 'recipes' for making their tools."

Erella Hovers of the Hebrew University of Jerusalem's Institute of Archaeology says the new study offers "some intriguing ideas", but she is not sure that the lack of stone tool tech advancement just after 2.5 million years ago "can be attributed exclusively to low-fidelity teaching modes" such as imitation or emulation.

Dietrich Stout, an assistant professor of anthropology at Emory University, has conducted studies on the cognitive mechanisms underlying tool making. He recently trained subjects to make stone tools over a two-year period and measured changes in their brain structure associated with learning. The results showed that brain systems associated with language were affected, supporting the proposed link between tool manufacture and language.

Stout says that Morgan and colleagues' study "adopts an experimental approach to questions that have otherwise been addressed largely through intuition or 'common sense,' for example, the question of whether teaching and language are important for learning Oldowan tech."

"The authors have taken an important step, but many questions remain," he adds.

This article originally appeared on DiscoveryNews.com