How one ancient language spread across Europe and Asia: Laura Spinney explains

Proto-Indo-European is an ancient language that many linguists believe was spoken in parts of the Eurasian steppe more than 5,000 years ago. They theorise that it spread widely and gradually evolved into the world’s largest language family, including tongues as diverse as Greek, Sanskrit and English.

Proto: How One Ancient Language Went Global by British science writer Laura Spinney captures the exciting journey of how this language spread west across Europe, displacing existing languages there, and later into Central and South Asia, where its descendants gave rise to the Iranian and Indo-Aryan languages.

In a recent interview with indianexpress.com, she said these ancient population migrations may have involved factors much more complex than violence. Geneticists, archaeologists, and linguists are working together to piece together these missing links in prehistory, and AI could be a big help, she says.

Laura Spinney: Languages are not inherently successful. Their speakers may be successful or not. A language’s fortunes grow or fall with those of its speakers. When I say successful, I mean that people are well-adapted to their environment, which means their numbers increase, their populations grow, and the language grows with it.

The language will also change over time: it may split into dialects, which might then become languages of their own, or it may die. The Proto-Indo-European languages were spoken by people who were immensely successful in that sense. They increased in number, spread out, and carried their language with them. They went east and west.

When they came west, they encountered other people speaking other languages. For example, in Europe, there were already roughly seven million settled farmers who spoke languages that had emerged from Anatolia several millennia earlier. It’s purely an estimate; there may have been tens of thousands of Indo-European speaking immigrants and perhaps seven million settled farmers. So how on earth did these newcomers manage to impose their language? This is the killer question.

About ten years ago, the rather simplistic explanation would have been violence. When geneticists see it from their studies of ancient DNA, you might imagine that only violence could have caused such a rupture. But ten years on, the explanation has become much more nuanced and multifactorial.

For example, there is one line of thought that pandemics might have been raging at that time, infectious diseases, including plague, or an early form of plague, and that this might have preferentially decimated the farmers’ population, leaving the nomads somewhat protected. This has not been proven yet, but there is some evidence. That’s another possible explanation for how they would manage to impose their language. Because so many of the indigenous population might have been simply wiped out by disease.

But another explanation, which I think is the most interesting, is a social explanation. The nomads are highly mobile and move with their herds. They have social conventions and institutions that maintain social cohesion across space and time. For example, they’re very welcoming to outsiders, they bring in wives, and they have a custom of reciprocal hospitality. By these mechanisms, they brought some of the local people into their own communities, perhaps through marriage, perhaps through capture, perhaps through enslavement.

They enlarged their population by bringing in these local people, who in their turn brought new knowledge, for example, of farming techniques, other kinds of food production methods, and the vocabulary to describe it, words that the nomads didn’t necessarily have. Europe, being a temperate zone, would have had a completely different flora and fauna from the steppe, which is treeless and much more hostile as an ecosystem. Those words also would have had to be learned from the locals. So, in many other ways, these languages would have shaped each other.

Q: But violence did likely play a role? And genetics may have captured it with a disproportionate ratio of parental haplogroups compared to autosomal DNA? Do you see language capturing it?

Laura Spinney: Yes, you’re absolutely right. Violence, we can’t rule out. It probably was one contributing factor, perhaps more in some parts of Eurasia than others. You can see, for example, in parts of northern Europe where immigration was particularly rapid, a very sharp, rapid turnover of Y chromosomes. What that would suggest is not pleasant, but it is probably that somehow the incoming men managed to prevent the indigenous men from passing on their Y chromosomes. We can only speculate about how they did it, whether it was murder, whether it was rape, or whether it was somehow excluding them. You can see that in the genetic signature.

What we know from captives through history is that they often took women in. Sometimes it’s a grey line between whether those women came willingly or not, whether they were enslaved, or whether they were enforced marriages. But those women would have come in; they would have been forced to learn the language of the dominant community, of their husbands.

But they might have spoken their mother tongue to their children. Their children would have then become bilingual, perhaps. Languages often influence each other through bilingual individuals. Those children would have learned both the new techniques, skills, and culture of their mother as well as their father, and the two would have become blended. Culturally and linguistically, the blending was ongoing across this succession of generations.

Q: Is it fair to describe Proto-Indo-European as a kind of father tongue in the way it spread?

Laura Spinney: Father tongue or mother tongue — it’s the last common ancestor of the Indo-European family. The ancestor of approximately 400 living languages and dialects, including many more that have died out in the interim.

Q: Your book does capture the tension in the late Bronze Age between the herders and the farmers. You also use a metaphor, ‘perekati pole’.

Laura Spinney: Perekati pole was the expression Natalia Shishlina, a Russian archaeologist, told me. In Russian, it’s the same expression, perekati polya, for the nomads of the steppe and for those tumbleweed plants that have no roots, that roll across the steppe and scatter their seeds.

Q: Your book says that linguists, archaeologists and geneticists are often barbarians to each other. Yet, those three are reconstructing humanity’s missing prehistory. How does the process work?

Laura Spinney: All three are getting a different aspect of prehistory. Obviously, the biologists are tracking the movement of people through the movement of their genes, notably ancient migrations. The archaeologists are looking at a different definition of identity, one that manifests in recurring assemblages of objects they excavate. They can say, “This site belongs to the culture that we name such and such”. And then at a certain date, this culture vanishes from the archaeological record. They have a sense of cultural identity: a culture can vanish, a new culture may emerge, but, of course, the genes flow on.

A language is transmitted in a different way, because you can learn a language from your parents, so in that sense, it’s transmitted like genes. But you can also learn a language horizontally, from a teacher or from a friend, or you can have several languages. And you can lose a language too. So the mechanisms of transmission are different. You can have a linguistic identity, a cultural identity and a biological identity, and they can be very close, or they can be quite different.

When linguists, archaeologists, and geneticists are trying to piece together prehistory, they’re getting at different aspects of it. They may not agree, but they need all three to tell the whole story. They’re barbarians to each other, but they need to be able to communicate in order to tell this story properly.

Q: Your work aligns broadly with that of (geneticist) David Reich and (anthropologist) David W Anthony. Are there points where you diverge from their conclusions?

Laura Spinney: It’s not necessarily that I disagree with them; it’s that there may be other theories for which the community feels there’s more evidence. For example, David Anthony, in his 2007 book, argues that the steppe nomads came west into Europe, and an early wave went down through the Balkans and into the Anatolian peninsula and seeded Anatolian. Many linguists still support that model.

But there is now a rival theory, which I think David Reich is more persuaded by, from genetic evidence. The genetic evidence would lend itself to the theory that Anatolians came into Anatolia the other way around the Black Sea, down through the Caucasus and into the Anatolian peninsula from the east. The remaining Indo-European languages then went west into Europe, but they separated, going around the Black Sea. It’s not a closed question.

Q: A big implication of your work is that large-scale migration has been a constant in human history, but we find that across the world, it provokes a great deal of anxiety. Why do you think that is?

Laura Spinney: Migration has been a fixture of human history, and we can see that in the genes. Why does it cause such tension? Because we are group animals, we identify ourselves in relation to a group, we have a sense of self and others, and we defend that sense. Immigration needs to be managed, especially in the crowded modern world. If it’s not well managed, there can be a genuine threat to the indigenous population, whether in the form of an economic threat, or a linguistic threat, a cultural threat, rival religions, or sheer numerical replacement — although that’s very rarely borne out.

The worries in Europe about the great replacement are completely unsupported by data, given the tiny percentage of the European population accounted for by immigrants. In a way, it doesn’t matter whether it’s true or it’s a perception, because the behaviour of the people who feel threatened may be the same.

That’s why it’s so important that we have politicians giving the right message, telling the reality and the facts in a way that allows people to understand. Where populations are ageing, we need immigrants to work. There are many benefits and drawbacks, and the goal should be to enhance the former and reduce the latter.

Q: How do you comment on languages being weaponised to create identities? The idea of otherisation through language?

Laura Spinney: It’s always happened. Let’s say that we are in a particularly fraught period of history. Everything is being weaponised, not just language. I think it’s interesting because you can push out a language by suppressing it. There are examples in history, but you can get resistance. You can get a group that becomes much more firmly attached to its language and much more determined to speak it within the group, to pass it on to its children, or even to go underground as a secret lingo. Then it’s a fight between opposing forces.

Q: Language spread because of many factors like prestige, institutions and social norms in the old days. Do you see parallels in how influence spreads today across culture, technology, and economics, rather than through force as it might have been?

Laura Spinney: Yes, absolutely. It’s interesting because literacy has only been widespread for a couple of hundred years. When you have a standard written form of a language, it tends to slightly slow down language evolution, because you’re all using the same standard.

That would be a braking force on language evolution. But on the other hand, we have the internet, social media, and greater visibility of variants, dialects and regional forms. It’s very difficult to predict the future of language change, because so many events can shape it.

Q: Researchers are increasingly using AI to detect patterns in language, genetics and archaeology. How should we guard against overconfidence when machines produce reconstructions which are elegant and potentially misleading?

Laura Spinney: This is an area where AI could be a real boon. AI is better than an individual human brain at identifying complex patterns. I think it will help us a lot in identifying what’s been inherited through time and detecting patterns we couldn’t otherwise detect.

But I know there are some linguists who push back against that, saying that AI only finds what it’s already seen examples of. It might not be terribly good at detecting innovations. It remains to be seen; the jury is out.

If evolution drives innovation and AI can detect the trend of evolution, wouldn’t it be able to predict an innovation? I don’t know. Only time will tell.