How many of us have wondered, to paraphrase Ursula Le Guin, why we huddle about the campfire? A recent study poses an answer to this question by looking at what hunter-gatherers talk about as they sit around the fire at night. The question isn't so much why we sit around the fire, but how the ability to control fire changed human life. Evidence indicates that our ancestors began using fire one million years ago, and were using it regularly by 400,000 BCE. Control of fire had profound effects on human survival, anatomy, and subsistence. By providing protection from predators, it reduced mortality rates and may have contributed to the evolution of a longer lifespan. By increasing the digestibility of food, it contributed to the reduction in gut volume, which in turn freed up energy that could be applied toward further brain expansion. And through the use of controlled burning, it enabled our ancestors to regulate the timing, distribution, quality, and quantity of resources. But little is known about its cultural effects. By providing warmth and light, control of fire added several waking hours to the hunter-gatherer day, raising the question of what our ancestors did with these bonus hours.
To address this question, Polly Wiessner compared 122 day and 52 nighttime conversations collected among Ju/'hoan hunter-gatherers in southern Africa. She found pronounced differences between daytime and nighttime conversation topics. Daytime discussion focused largely on gossip (34 percent), economic matters such as foraging plans, resource availability, and hunting strategies (31 percent), and joking sessions (16 percent). With the fall of darkness, however, an abrupt shift occurred, with 81 percent of talk consisting of stories. In contrast, storytelling constituted only 6 percent of daytime conversations. Although we can't know for sure what ancestral hunter-gatherers talked about as they sat around the fire, Wiessner's findings suggest that they primarily chose to tell stories. Is it possible that this extra time allotted to storytelling impacted subsequent human evolution?
Although it may sound farfetched, this question makes perfect sense in the context of the pronounced human ability to extract, manipulate, and share information. By two million years ago, our ancestors had begun colonizing a new feeding niche, shifting to foods with highly concentrated calories and nutrients, such as meat, tubers, and nuts. Since their primate heritage left them without the anatomical features used by other species to access these foods--e.g., sharp claws, powerful jaws, large canines, high-speed locomotion, a keen sense of smell--they used their large brains instead. They invented tools and strategies such as digging sticks, stone knives and hammers, projectile weapons, and tracking to bypass their anatomical limitations and gain access to these rich resources. But occupation of this new niche--known as the foraging niche--came with a price: the use of these tools and strategies required extensive knowledge of animal behavior, plant and mineral properties, weather, topography, route finding, and--because humans are highly cooperative animals--social rules. It is impossible for a person to learn everything needed to make a living as a hunter-gatherer through direct experience, so as humans adapted to this new ecological niche, they evolved a means of bridging the knowledge gap: social learning, or information sharing.
Learning through direct experience, or trial-and-error, is a slow and unpredictable process, because the appropriate learning experience might not occur by the time it is needed. Social learning circumvents this constraint by providing access to the experience of others--including the experience of previous generations. In so doing, social learning exponentially increases the amount of knowledge an individual can acquire by adulthood. For most of its existence, information sharing has been oral. We know this because ancestral H. sapiens emerged around 300,000 years ago, while writing emerged a mere 5,000 years ago and literacy did not become widespread until after the invention of the printing press in the 1400s. For most of their existence, then, humans have been sharing knowledge through the spoken word.
Much of my research has investigated the proposition that, once storytelling emerged, it served as an important vector of knowledge transmission. One prediction that follows from this hypothesis is that hunter-gatherer oral tradition will recount experiences that contain information useful for addressing recurrent problems of hunter-gatherer life. In other words, we would expect to find cross-cultural patterns in story content, and we would expect this content to reference local solutions to problems posed by the foraging niche. This is indeed what we find: cross-culturally, forager oral tradition contains a wealth of information about animal behavior and characteristics, plant properties and growth habits, topography and landmarks, weather patterns, famine, warfare, child care, and social rules. Wiessner reaches a similar conclusion: "Through stories and subsequent discussion, people collected experiences of others and accumulated knowledge of options that others had tried." She found that the bulk (60 percent) of evening conversation focused on social matters such as kinship obligations, marriage practices, meat sharing, land rights, gift exchange, and healing rituals. The remaining 40 percent focused on "economic exploits such as hunting stories, close calls with wild animals, or adventures while traveling to other areas." Wiessner's study thus gives teeth to the claim that storytelling is an important medium of knowledge transmission in forager societies by showing that, in at least one forager group, people devote a considerable portion of their waking hours to this activity.
So how did all this extra time devoted to storytelling affect life in early human groups? One obvious possibility is that it stabilized existing knowledge by increasing opportunities for transmission, thereby preventing it from being lost upon the death of the individuals who possessed it. By the same token, it would have expanded the collective knowledge pool, as new information was acquired and shared. This in turn may have accelerated the rate of technological and cultural change, as time and energy formerly spent reinventing the wheel were redirected toward exploration and the dissemination of new discoveries.