Tuesday, September 3, 2013

Toolmaking and Speech

When did primates start talking? It is a vexed question, with answers from "experts" coming in everywhere from 50,000 to 3 million years ago. Now, some possible evidence:
Unlike ancient bones and stone tools, language does not fossilize. Researchers have to guess about its origins based on proxy indicators. Does painting cave walls indicate the capacity for language? How about the ability to make a fancy tool? Yet, in recent years, scientists have made some progress. A series of brain imaging studies by Dietrich Stout, an archaeologist at Emory University in Atlanta, and Thierry Chaminade, a cognitive neuroscientist at Aix-Marseille University in France, have shown that toolmaking and language use similar parts of the brain, including regions involved in manual manipulations and speech production. Moreover, the overlap is greater the more sophisticated the toolmaking techniques are. Thus, there was little overlap when modern-day flint knappers were making stone tools using the oldest known techniques, dated to 2.5 million years ago and called the Oldowan technology. But when knappers used a more sophisticated approach, called Acheulean technology and dating to as much as 1.75 million years ago, the parallels between toolmaking and language were more evident. Stout and Chaminade have used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scans, although not on the same subjects at the same time.
Further testing has shown that the brain patterns of tool makers most resemble speech during the first 10 seconds of the task, when they are strategizing about how to proceed with their rocks.

I don't find this remotely convincing, even though it supports my own view, that language is millions of years old. I think our growing understanding that other animals, especially dolphins and chimps, do things that are sort of like language ought to have put paid to the notion that language was "invented" by modern humans. I think it must have evolved gradually over the past 5 million years. As manufacturing tools did.

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