Hunter-gatherers may have facilitated cultural revolutions via small social networks: Study

Hunter-gatherer human ancestors from around 3,00,000 years ago may have facilitated a cultural revolution by developing ideas in small social networks, and regularly drawing on knowledge from their neighbouring camps, a new study says.

The research, published in the journal Science Advances, mapped close-range social interactions between individuals of Agta hunter-gatherers in the Philippines using radio sensor technology every hour for one month.

Anthropologists, including those from the University College London (UCL) in the UK, also observed inter-camp migrations and visits almost on a daily basis.

They found that the social structure of the hunter-gatherers, built around small family units linked by strong friendships and high in-between camp mobility, was key to the development of new cultural ideas.

According to the scientists, this is because the social structure allowed for the co-existence of multiple traditions or solutions to a similar problem in different parts of the network.

"It is fair to say that 'visits between camps' is the social media of current hunter-gatherers, and probably of our extinct hunter-gatherer ancestors," said study co-author and anthropologist Andrea Migliano from the University College London.

"When we need a new solution for a problem, we go online and use multiple sources to obtain information from a variety of people. Hunter-gatherers use their social network exactly in the same way," Migliano explained.

The researchers said these constant visits between camps are essential for information to be recombined and continuously generate cultural innovations.

In the study, the scientists selected pairs of individuals from the Agta hunter-gatherer community, based on the strength of their social ties, to combine different medicinal plants and share the discovery of any new super medicine with their close family ties.

They simulated this process over an artificial and fully connected network of a similar size, where all individuals were connected to each other and immediately transmitted any discoveries to all network members.

The findings revealed that the rates of cultural evolution were much higher across the real hunter-gatherer social networks.

While fully connected networks spread innovations more quickly, the real hunter-gatherer networks promoted the independent evolution of multiple medicines in different clusters of the network -- different camps, households, family clusters -- the study noted.

These independently developed medicines could be later recombined producing a more complex culture, the scientists said.

"Previous studies have shown that fluid social structures already characterised expanding Upper Palaeolithic human populations and that long-range cultural exchange in the Homo sapiens lineage dates back to at least 3,20,000 years ago," said study co-author Lucio Vinicius from UCL.

"However, the link we found between cultural evolution and the fluid sociality of hunter-gatherers indicates that as hunter-gatherers expanded within and then out of Africa, this social structure of small and interconnected bands may have facilitated the sequence of cultural and technological revolutions that characterises our species," he said.

According to the researchers, the study sheds light on the importance of the dynamics of social interactions in human cultural and technological innovation.

"Humans have a unique capacity to create and accumulate culture. From a simple pencil to the International Space Station, human culture is a product of multiple minds over many generations, and cannot be recreated from scratch by one single individual," said Mark Dyble, another co-author of the study from UCL.

"This capacity for cumulative culture is central to humanity's success, and evolved in our past hunter-gatherer ancestors. Our work shows that the kind of social organisation that is typical of contemporary hunter-gatherers serves to promote cultural evolution," Dyble said.