An experiment casts doubt on the history of stone tools

Electronics, aircraft, internal combustion engines, and the wheel are descendants of a much more primitive technology: stone tools. Early stone tools may seem simple, but their invention marked a significant milestone in the history of our species.

Archaeologists have long believed that figuring out how to make stone tools—what kind of materials to use, where to find them, and how to reshape rocks to make something useful—was a team effort of many individuals working together and learning from each other. A new batch of experiments in which volunteers were brought into a lab to make stone tools suggests that this may not be the case. The findings were published Wednesday in the peer-reviewed journal Science Advances.

“We shifted the timeline of humanity’s cognitive beginnings forward in time by hundreds of thousands, if not even a million years,” archaeologist William Snyder, one of the co-authors, told IE.

However, not everyone was convinced.
Archaeological experiments yield surprising results

The researchers brought 28 participants into the lab. Each was given the raw materials they needed to accomplish a simple task: cutting a thread to access a reward. Working on their own, the participants had to figure out how to use materials to make a tool capable of cutting thread. Here’s the problem: They didn’t receive any instructions on how to do this. The researchers wanted to see if these ordinary people could figure out how to make the kind of tools that ancient hominins made two million years ago.

The results of the experiment were amazing. During the four hours they had to work, all 28 research participants (including participants who had never heard of stone tools before) independently figured out the tool-making techniques used by the early tool-makers.

“The tool-making techniques these individuals used were largely the same as those that would have been used more than 2 million years ago. Right now, we see this as strong evidence of principle that one can reinvent techniques without even seeing them,” Snyder says.
The results of the experiments are not clear cut

Archaeologist Justin Partiger, who also researches early toolmaking but was not involved in these experiments, says he’s glad the researchers behind the new study are bringing new data to a long-running debate — but he’s not convinced by the study’s conclusions.

“If you look at these results, I see a set of techniques that were replicated by these individuals that don’t match what we found [in the archaeological record] 2.6 million years ago,” he says. While participants in the new study explored the four main techniques used by ancient tool makers, modern tool makers showed no preference for the most common technique used more than 2 million years ago, during the period of interest to the researchers.

As the number of artifacts in the archaeological record grows, archaeologists are increasingly turning to the number of different types of tools to make sense of ancient technology. “The archaeological record is about numbers and frequencies. It’s not about rare events,” says Partiger. This is important here because study participants did not develop techniques at rates that matched what was found in the study authors’ attention span. “The majority of the behavior that emerges in this experiment is actually more like a 3.3 million year period,” he says. Unfortunately, researchers don’t know much about that earlier period because it’s represented by a single site: Lumekwe, in northern Kenya.

“I think a lot of people would be very happy to argue that, yeah, there’s probably a lot of individual experimentation going on over 3 million years ago with hominins that moved further away from our lineage,” he says.

The study’s authors disagree, writing that “[a] new lines of evidence are firm, and the first definitive evidence of technology transfer, and with it, the cumulative culture of knowledge must be pushed to a later time.” They call for more experiments to determine how the cultural transmission of knowledge began recently