Now, I want to tackle a bad legacy in archaeology: the term “Stone Age.” We break up early human prehistory into the Paleolithic, Mesolithic, and Neolithic based on the use of stone tools—and, later, farming. But, this is a poor system based on an observational bias called the Streetlight Effect.
The Streetlight Effect is named for an old joke about a guy found searching for his keys at night under a street light. The person finding him asks where he last knew he had the keys. The guy says, “Over there on the other side of the street, but the light is better over here.”
The term “Stone Age” is derived from the fact that stone tools survive better than tools created from other materials. If some creature makes a tool from plant fibers or bone, these tools are far less likely to present in the fossil record than stone tools. It’s on the “dark side” of the archeological street.
HUMANS AIN’T SPECIAL
In the wake of the discovery that capuchin monkeys have been using stone tools at least since before Columbus arrived in the New World, it’s time we accepted that humans ain’t special.
We know that many non-human animals also use tools. Some birds employ thorns to kill prey or pin their carcasses for flaying. Herons will use food to lure fish. Chimpanzees fashion pieces of grasses to plunge into termite nests to trick them into biting down the grass; the prey are then pulled from the nest into the chimp’s mouth. Chimps will also process leaves by chewing them to create a sort of sponge to soak up water for drinking.
Quite remarkably, elephants have been observed manufacturing stick tools to dig holes for drinking water, then chewing tree bark into balls to plug the holes to keep the water from evaporating so they can use the same water hole later.
From apes to elephants to birds, animals use tools. There’s an ongoing debate about how much of this tool use and manufacture is cultural vs. instinctual (particularly among invertebrates) but it’s pretty clear that some non-humans are fellows in cultural tool use.
A BETTER SYSTEM: THE TOOL AGE
To replace the term “Stone Age,” I propose the term “Tool Age.” Or, more technically, the Ergaleic from the Greek εργαλείο meaning “tool,” as the various obsolete “-lithic” terms are derived from the Greek λίθος for “stone.”
The Ergaleic would encompass not only early humans but also other tool-using species. To be fair, we could reasonably assume that the Ergaleic extends far into human prehistory beyond what we know as the Stone Age. It’s a certainty that human ancestors used non-stone tools that did not survive to become fossil evidence. Streetlight Effect be damned!
The Ergaleic could be broken down as follows:
Chrisergaleic, from the Greek χρήση for “use,” would be the “Tool Use Age” to encompass the simplest cultural transmission: simply utilizing an unmodified object for some survival purpose. This would be where those tool-using capuchin monkeys would fall, possibly as well as thorn-using birds.
Kanergaleic, from the Greek κάνω for “do” or “make,” would be the “Tool Making Age” to encompass the transformation of objects as tools. This would roughly align with the Paleolithic, but would also include the chimpanzee and elephant water-gathering techniques described above.
Lithergaleic could be used as a technical term in archaeology to recognize the availability of stone-based fossil evidence. It would overlap the Chrisergaleic and Kanergaleic. That capuchin monkey discovery would fall into the Lithergaleic.
Zoergaleic, from the Greek ζωή for “life,” would be the “Domestication Age” to indicate the mutualism in which one species breeds another species as a cultural tradition. This would roughly align with the Neolithic.
SHARE and promote this system as a better way of thinking about the evolution of tool use!