When I was at Cambridge (almost two years ago!), I stumbled on the work of cognitive archaeologists Lambros Malafouris and Colin Renfrew. Renfew is a professor at Cambridge with whom I had a really interesting lunch, while Lambros is a fellot at Oxford (and one of those brilliant young academics who in a more generous and expansive era would have gotten tenure years ago). They in turn led me to studies of ancient multitasking, particularly Monica Smith's reconstruction of multitasking in everyday ancient life and Lyn Wadley's work on halfting.
So naturally new research indicating that halfting is a much older practice than we realized caught my eye. Science has a new article on the subject, which is summarized on the AAAS Web site:
Early humans were lashing stone tips to wooden handles to make spears and knives about 200,000 years earlier than previously thought, according to a study in the 16 November issue of Science.
Attaching stone points to handles, or “hafting,” was an important technological advance that made it possible to handle or throw sharp points with much more power and control. Both Neandertals and early Homo sapiens made hafted spear tips, and evidence of this technology is relatively common after about 200,000 to 300,000 years ago.
Jayne Wilkins of the University of Toronto and colleagues present multiple lines of evidence implying that stone points from the site of Kathu Pan 1 in South Africa were hafted to form spears around 500,000 years ago. The points’ damaged edges and marks at their base are consistent with the idea that these points were hafted spear tips.
So why does this matter? The Guardian explains,
The invention of stone-tipped spears was a significant point in human evolution, allowing our ancestors to kill animals more efficiently and have more regular access to meat, which they would have needed to feed ever-growing brains. "It's a more effective strategy which would have allowed early humans to have more regular access to meat and high-quality foods, which is related to increases in brain size, which we do see in the archaeological record of this time," said Jayne Wilkins, an archaeologist at the University of Toronto who took part in the latest research.
The technique needed to make stone-tipped spears, called hafting, would also have required humans to think and plan ahead: hafting is a multi-step manufacturing process that requires many different materials and skill to put them together in the right way. "It's telling us they're able to collect the appropriate raw materials, they're able to manufacture the right type of stone weapons, they're able to collect wooden shafts, they're able to haft the stone tools to the wooden shaft as a composite technology," said Michael Petraglia, a professor of human evolution and prehistory at the University of Oxford who was not involved in the research. "This is telling us that we're dealing with an ancestor who is very bright."
This joins recent work on arrow-making, which both demonstrates that the manufacture and use of arrows is older than we thought, and that its complexity suggests ancient multitasking abilities:
"These operations would no doubt have taken place over the course of days, weeks or months, and would have been interrupted by attention to unrelated, more urgent tasks," observes paleoanthropologist Sally McBrearty of the University of Connecticut in a commentary accompanying the team’s report. "The ability to hold and manipulate operations and images of objects in memory, and to execute goal-directed procedures over space and time, is termed executive function and is an essential component of the modern mind," she explains.
McBrearty, who has long argued that modern cognitive capacity evolved at the same time as modern anatomy, with various elements of modern behavior emerging gradually over the subsequent millennia, says the new study supports her hypothesis. A competing hypothesis, advanced by Richard Klein of Stanford University, holds that modern human behavior only arose 50,000 to 40,000 years ago, as a result of some kind of fortuitous genetic mutation that kicked our ancestors’ creativity into high gear. But discoveries of symbolic items much older than that supposed mutation–and older than the PP5-6 arrowheads for that matter–have cast doubt on Klein’s theory. And other finds hint that Neandertals, too, engaged in symbolic behaviors, which would suggest that the capacity for symbolic thinking arose in our common ancestor perhaps half a million years ago.