Origins of cumulative culture in human evolution: Researchers identify contributions to contemporary culture and technology

Each of us individually is the accumulated product of thousands of generations that have gone before us in an unbroken line. Our culture and technology today are also the result of thousands of years of accumulated and remixed cultural knowledge.

But when did our earliest ancestors begin making connections and building on the knowledge of others that set us apart from other primates? Cumulative culture – the accumulation of technological adaptations and improvements over generations – enabled people to adapt to a diversity of environments and challenges. But it is unclear when cumulative culture first developed during hominin evolution.

This is evident from a study published this week in the Proceedings of the National Academy of Sciences by researcher Charles Perreault of Arizona State University and doctoral candidate Jonathan Paige, concludes that humans began rapidly acquiring technological knowledge through social learning about 600,000 years ago.

“Our species, Homo sapiens,” Perreault said, “has managed to adapt to ecological conditions – from tropical forests to Arctic tundra – that require solving different types of problems. Cumulative culture is critical because it allows human populations to build on and recombine the solutions of previous generations and develop new complex solutions to problems very quickly.

“The result is that our cultures, from technological problems and solutions to the way we organize our institutions, are too complex for individuals to figure out on their own.” Perreault is a research scientist at the Institute of Human Origins and an associate professor at the School of Human Evolution and Social Change.

To investigate when this technological turn might have begun, Paige and Perreault analyzed changes in the complexity of stone tool-making techniques over the last 3.3 million years of the archaeological record to investigate the origins of the cumulative culture.

To provide a basis for the complexity of stone tool technologies achievable without cumulative culture, the researchers analyzed technologies used by non-human primates – such as chimpanzees – and stone tool making experiments involving inexperienced human flint beaters and random flakes .

The researchers divided the complexity of the stone tool technologies into the number of steps (PUs or procedural units) each set of tools involved. The results suggested that from about 3.3 to 1.8 million years ago – when Australopiths and the earliest Homo species existed – stone tool production sequences remained within the baseline range (1 to 6 PUs).

From approximately 1.8 million to 600,000 years ago, production sequences began to overlap and slightly exceed the complexity baseline (4 to 7 PUs). But after about 600,000 years ago, the complexity of the production sequences increased rapidly (5 to 18 PUs).

“About 600,000 years ago, hominin populations began to rely on unusually complex technologies, and it is only after that time that we see a rapid increase in complexity. Both findings are consistent with what we expect to see in hominins that rely on cumulative culture.” said Paige, a postdoctoral researcher at the University of Missouri and ASU Ph.D. to graduate.

Tool-assisted foraging may have initiated the earliest onset of cumulative culture evolution. Early hominins, 3.4 to 2 million years ago, likely relied on foraging strategies that required resources such as access to meat, marrow, and organs, leading to changes in brain size, lifespan, and biology that paved the way for cumulative culture.

Although other forms of social learning may have influenced tool production, it is not until the Middle Pleistocene that there is evidence for a rapid increase in technological complexity and the development of other types of new technologies.

The Middle Pleistocene also shows consistent evidence of controlled use of fire, hearths, and domestic spaces, likely essential components of the development of cumulative culture. Other types of complex technologies also developed in the Middle Pleistocene, including wooden structures built with tree trunks carved using shafted tools, which are stone blades attached to wooden or bone handles.

All this suggests that cumulative culture emerged at the beginning of the Middle Pleistocene, possibly before the divergence between Neanderthals and modern humans.