The Great Leap Forward

We seem to like very much the idea of making a “great leap forward.”  In 1958 Chairman Mao used the phrase to describe his plan to modernise China’s economy. And “New Age” enthusiasts like to think that humanity is now making a “quantum leap” in consciousness. But the original “great leap forward”, according to many anthropologists, occurred sometime between 75,000 and 50,000 years ago when Homo sapiens became a species driven by language and culture. An explosion in our capacity for symbolic thought and self-awareness, accompanied by breakthrough developments in spoken language, brought with it an accompanying explosion in cultural creativity.

Over what period of time these advancements took place remains a matter of debate among anthropologists. One theory holds that a leap into “behavioural modernity,” or what is sometimes called the Upper Paleolithic Revolution, occurred almost suddenly some 50,000 years ago – perhaps as a result of a genetic mutation or a reorganization of the brain that led to a major advance in language. Proponents of this theory, known as the “big bang” theory of human mental evolution, base their evidence on the abundance of artefacts, such as artwork and bone tools, that appear in the fossil record after 50,000 years ago – indicating, they suggest,  that prior to this date Homo sapiens lacked the cognitive skills required to produce such artefacts. Jared Diamond, an evolutionary scientist at UCLA, contends that, prior to this time, there is little evidence of cultural change. But then, coinciding more or less with our exodus from Africa to colonise the world, there is a sudden flowering of tool-making, sophisticated weaponry, sculpture, cave painting, body ornaments, and long-distance trade

An alternative theory known as the Continuity Theory holds that “behavioural modernity” has resulted from a gradual accumulation of knowledge, skills, and culture occurring over hundreds of thousands of years of human evolution. Advocates of this view, such as geneticist Stephen Oppenheimer, contend that evidence of modern behaviour can be found at a number of sites in Africa and the Levant from a much earlier time. A ritual burial with grave goods, for example, has been uncovered at Qafzeh in Israel and dated to 90,000 years ago. Continuity theorists believe that what appears to be a later technological revolution is probably the result of increased cultural exchange within a growing human population.

The truth may lie somewhere between the extremes of these two theories. From about 75,000 years ago there appears to have been a marked acceleration in the development of human language, cognition, and culture. The evidence for this consists primarily of artefacts found at Blombos Cave, 30 meters above the sea on the southern tip of South Africa. Here we find the earliest undisputed evidence of art in the form of bracelets, beads, rock art, and ochre used as body paint.

Beads made from the shells of tiny molluscs, dating from 76,000 years ago, were found in clusters. Pierced holes in the shells, together with smooth worn patches, suggest that the beads were strung together into necklaces or bracelets which may have rubbed against clothing. Blombos cave is also famous for its abstract engravings on red ochre from the same time. Together with the beadwork, it suggests that inhabitants of the cave had a complex sense of symbolism and a sufficiently developed language to describe the symbolic meaning that the beads and engravings represent. Here was the first tangible evidence of advanced, abstract thought.

Why should our ancestors have gone out of their way to collect high-quality red iron oxides? The red ochre has got to be culturally significant. At first it looks like any lump of pinkish rock. But look more closely and you see a cross-hatched pattern carefully etched onto its surface. It is regarded as the first evidence of Stone Age lipstick – as if, almost suddenly, people wanted to paint their bodies. Coincident with this is evidence that clothing also originated in Africa 75,000 years ago. It would of course have been useful when Homo sapiens left Africa and ventured into colder climes – but that migration did not take place until some 15,000 years later. It would seem that our taste for jewellery, fashion, art and cosmetics all emerged at about the same time. But why? Was it all about sexual attraction and signaling one’s genetic fitness with rare adornments? Or was it evidence of prestige and status? Even in this egalitarian society, some people would be more successful than others, and they may have wanted to signal their success with prized material items. This could, in other words, be the first evidence of social ranking marked by material possessions.

There were also significant advances in tool-making at this time. The harpoon had been invented 90,000 years ago. But now, just 70,000 – 65,000 years ago, using the earlier technology of heating silcrete to temperatures of 450-degrees Fahrenheit, small stone tools and points were invented, making possible the manufacture of lightweight bows and arrows and projectile spears.

Considering all these developments, along with the evidence of more permanent dwellings, hearths, and group living, and we begin to see the first signs of an organised society, communicating through language, symbolism, and rituals. Whether such developments occurred abruptly or more gradually, it seems clear that there was a significant advance in human cognition and culture from 75,000 years ago, leading to the African exodus of 60,000 years ago. The question is “Why?”

Climate was almost certainly a factor. With the onset of a new Ice Age some 80,000 years ago, our relatively settled life on the African savannah was forced to change. By 70,000 years ago it was getting downright nippy in the northern hemisphere. Great sheets of ice were bearing down on what would later be Seattle and New York.  In Africa a 10-degree Celsius drop in the average world temperature, as well as the fallout from the eruption of a super-volcano in Sumatra, brought extensive drought to the interior, forcing early humans to coastal regions where they could survive on seafood. Genetic evidence, however, suggests that they nonetheless suffered a massive decline in population at this time – dwindling to as few as 2000 individuals. Homo sapiens was literally on the brink of extinction. The upside was that, in adapting to these new and difficult conditions, our species also became a whole lot smarter. The deep-freeze and drought may have been the catalyst for the Great Leap Forward, favouring intelligence and more complex social structures as life became more difficult.

It may also be that just a few small genetic mutations at this time gave us these amazing minds and the power of abstract conceptual thought.  Whatever the trigger, none of these changes could have occurred without the development of language and the social networks that language makes possible. More specifically, the Great Leap Forward depended on our mastery of syntax – the ability to create multi-word sentences that are structured with a subject, verb, and object. How those parts of speech are arranged varies from one language to another. English and most other languages are characterised by a subject-verb-object (SVO) syntax. An SOV structure is used by a few languages; VSO and VOS are used by about 15% of languages; and OSV is the rarest of all. But whatever the structure, our ability to communicate complex meaning depends on our understanding and use of syntax. It’s what distinguishes human from ape communication.

Just why we should have crossed the syntax barrier at this point in our history remains unclear. It parallels the development of language in children and seems to require the maturation of certain brain structures. Children begin to speak by babbling. At about 12 months, they begin to use actual words. Over the next year there is a massive expansion of single-word vocabulary and the emergence of two-word sentences. Between two and three years of age, children begin to put together three-word sentences with syntax. This is the stage in individual development that corresponds with the Great Leap Forward in humanity’s development.

It was all necessary in order to make possible the next stage in our development when, some 60,000 years ago, we began to leave our African homeland and spread into Europe and Asia. During the next couple of thousand years we had walked around the coast of South Asia and reached Australia. A later wave of expansion took us into the Middle East and then on into Europe, Asia, and the Americas. A species that had almost been made extinct rallied to populate the entire world. And what set it all in motion happened first in Africa – this Great Leap Forward that marked our initiation as modern humans