Recent studies suggest that it was women who were mainly responsible for the spread new ideas, culture, and technical innovations in the Stone-Age. And furthermore, it appears that female social skills, allied to an institutional pattern of female mobility, played an important role in the transition from Stone-Age to Bronze-Age Europe.
A study published this month in PNAS suggests that it was women, travelling far afield to marry and raise families while their men-folk stayed at home, that were crucial in the transformation from the European Stone-Age into the Bronze-Age. The study used paleo-genetic and isotope data from human remains to confirm that, rather than a wholesale immigration of peoples using the new metal technologies, it was individual female mobility which brought new ideas, technologies and culture into Europe in the Stone-Age.
So, rather than innovations and cultures being been spread by incoming populations who either wiped out and replaced the locals, or simply exchanged and traded gifts with them, it would seem that a very different sort of exchange took place as females routinely left their homelands to marry and raise families in unfamiliar neighbourhoods. Consequently both Neolithic and Bronze-age men seem to have played a lesser role than their female relatives in the spreading of innovation and ideas. But female contribution to the spread of culture and technology was not limited to the Bronze-Age, it originated way back to when hominins split off from their chimpanzee cousins, and it all stemmed from female ability to socialise with strangers.
Female Homo sapiens and their part in male socialisation
For culture to accumulate, large interaction networks are required, and evolutionary behavioural scientists have long attempted to understand how and why this cooperative temperament might have spread in early hominin societies but not in chimpanzees. It now seems that human females were simply cashing in on a trait that both chimp and human females inherited from their common ancestor, which is the ability to integrate socially into new groups. This knack for socialising with strangers eventually developed into into a powerful survival tool as Homo sapiens began to multiply and spread throughout the world.
But why did humans develop this skill, while their chimpanzee cousins did not? After all, the earliest hominins lived in a similar social set-up to modern chimpanzees, i.e. males form troops around their own male kin, and live in the area in which they were born, while females migrate from their birth area and birth troop to join male kin-bonded troops. But while chimpanzees can get all they need to eat within a fixed local area, humans evolved to become very reliant on animal protein because of their increasingly larger brain sizes, and so they became mobile hunter-gatherers.
Portable (so-called 'venus') palaeolithic female figurines
Sexual equality in hunter-gatherer communities
A study completed a couple of years ago showed how increased group mobility goes hand-in-hand with sexual equality. Using modern mobile hunter-gatherers as models, the study found their communities to be surprisingly egalitarian, with both men and women having equal status and an equal say in who can join their ‘bands’. And an interesting outcome of this is that both women and men had male and female relatives within their bands as well as people totally unrelated to them. Furthermore this ability to cooperate is not reserved for members of their own families, but extends to unrelated individuals, who share food extensively within camp, and hunt, gather, and fish cooperatively. In fact unrelated individuals in these bands have also been found to share parenting duties.
This study explains how a shift away from a chimpanzee-like system would provide the selective context for expanded social networks, cumulative culture, and cooperation among unrelated individuals. And the reason behind these developments in male sociability is that, where a woman is linked by marriage or kin with a number of men who are not related to each other, it leads to a breakdown in hostility between traditional male-kin-bonded groups; the sort of hostility commonly found in rival chimpanzee groups. Then, if friendly visiting between groups is common and social network sizes are large, frequent interaction allows for increased observation of rare innovations that are unlikely to be discovered by individual learning.
Women under patriarchy
However, this description of Palaeolithic hunter-gatherer society would seem to be completely different from what is known about Neolithic and even Bronze-age society. In contrast to the egalitarian hunter-gatherers, the farmers of the Neolithic communities appear to have lived more like chimpanzees, in settled patriarchal communities where men were related and women joined their groups from elsewhere. But it has long been known from archaeological evidence that even these two very different sorts of society had a relatively seamless transition in some parts of Europe, and a study published in June of this year was able to confirm that a great deal of physical and social interaction took place between at least two of these communities.
By sequencing ancient DNA isolated from four ancient humans from Romania, researchers led by the University of Potsdam's Michael Hofreiter found that there were complex interactions between hunter-gatherers and farmers in that region of Europe. "We expected some level of mixing between farmers and hunter-gatherers, given the archaeological evidence for contact among these communities," Hofreiter said in a statement. "However, we were fascinated by the high levels of integration between the two communities as reconstructed from our ancient DNA data ... our study shows that such contacts between hunter-gatherers and farmers went beyond the exchange of food and artifacts".
Detail of Minoan 'campstool' fresco, III Palace period, Knossos
So the concept of inter-marriage between incoming farming communities and local hunter-gatherers would tie in with the recent study this September into the role of female mobility in spreading Bronze-age culture into Neolithic communities, and it is likely that cultural exchange between all three types of communities would have been facilitated by female mobility and female socialisation. In the words of Philipp Stockhammer, who headed up the September study:
“This trend of women moving from one region to another wasn’t just a temporary thing that took place over a few hundreds of years... It appears that at least part of what was previously believed to be migration by groups was based on an institutionalised form of individual (female) mobility.”
Main Image; Figurines from the Ain Ghazal archaeological site in Jordan 7,000 -5,000 BCE
References:
Female exogamy and gene pool diversification at the transition from the Final Neolithic to the Early Bronze Age in Central Europe
PNAS, DOI: 10.1073/pnas.1706355114
Sex equality can explain the unique social structure of hunter-gatherer bands
Dyble M. et al. Science 15 May 2015: Vol. 348, Issue 6236, pp. 796-798 DOI: 10.1126/science.aaa5139
http://science.sciencemag.org/content/348/6236/796?variant=full-text&sso=1&sso_redirect_count=1&oauth-code=28a36df2-a1ad-4664-afa0-4dfa0fea6bbc#ref-24
Neanderthal-Derived Genetic Variation Shapes Modern Human Cranium and Brain,
Gregory M.D. et al. Scientific Reports (2017). DOI: 10.1038/s41598-017-06587-0
Paleogenomic Evidence for Multi-generational Mixing between Neolithic Farmers and Mesolithic Hunter-Gatherers in the Lower Danube Basin
Current Biology, Volume 27, Issue 12, p1801–1810.e10, 19 June 2017