A change in our diet may have changed human languages

As the saying goes, we are what we eat – but is this aspect of our identity reflected in the languages ​​we speak?

In a new study in Science, a team of linguists from the University of Zurich uses biomechanical and linguistic data to demonstrate that the rise of agriculture thousands of years ago increased the risks that populations would begin to use sounds such as F and v. The idea is that agriculture introduces a range of softer foods into human diets, which alters the way humans 'teeth and jaws wear out with l' régimes introduit dans dans dans dans dans,,,,,,,,,,,,,,,,,,,,,,,,,,,. age, to make these sounds slightly easier to produce.

"I hope our study will trigger a broader discussion about the fact that at least some aspects of language and speech – and I insist, some"We have to be treated as we are dealing with other complex human behaviors: to make a connection between biology and culture," says lead author Damián Blasi.

If confirmed, the study would be one of the first to show that a culture-induced change in human biology altered the arc of global languages. Blasi and colleagues point out that changes in the wear of teeth do not have it guarantee language changes, they also did not replace other forces. Instead, they argue that the change in tooth wear has improved the probabilities of sounds such as F and v emerge. Some scientists in other fields, such as dental wear experts, are open to this idea. (Today, many scientists are fighting to save endangered languages.)

"[Tooth wear] is a common model with deep, evolving roots; it's not specific for humans [and] Hominins, but also in great apes, "say in a joint email the paleoanthropologists of the University of Zurich, Marcia Ponce de Leon and Christoph Zollikofer, who did not participate in the study. "Who could have imagined that after millions of years of evolution, this would have consequences on the linguistic diversity of human language?" (Another study shows how ancient rock art can to be related to language.)

Although the study is based on various assumptions, "I think the authors build a very plausible case," says Tecumseh Fitch, an expert in bioacoustics from the University of Vienna who did not participate in the work. "This is probably the most compelling study to date to show how biological constraints on language change might themselves change over time because of cultural changes.

But many linguists have gone to skepticism, anxious to rediscover the differences between languages ​​and differences in biology – a line of thought in the field that has led to ethnocentrism or worse. On the basis of the wide variety of languages ​​and dialects of the world, most linguists now think that we all share the same biological tools and the same abilities of sound creation for spoken languages.

"We really need to know that the little [average] The differences observed in studies like this one are not overwhelmed by the ordinary diversity within a community, "says Adam Albright, a linguist at MIT and not involved in the study, in an email.

Teeth can feel firmly embedded in the skull and jaw, but as anyone who wears suspenders can tell you, teeth can move and drift in the jaw a little as people get older. Humans are often born with a slight overbite, but as the teeth naturally wear out, they tilt towards a more vertical orientation. To compensate, the lower jaw shifts forward so that the rows of upper and lower teeth are aligned edge to edge.

During most of the history of our species, this edge-to-edge configuration was the norm in adulthood, as shown by many prehistoric skulls studied over the last three decades. But when societies adopted new farming techniques, such as grain farming and animal husbandry, diets changed. Once the old menus were dominated by porridge, cheese and other soft foods, people's teeth were less worn out, which allowed more people to keep an overdeliver until they were gone. ;adulthood.

According to the thought, a more common overblanking opens the way to sounds such as F and vthat you do when you return your lower lips under their upper teeth. If your most prominent teeth exceed a little more, it is theoretically easier to produce these sounds, which linguists call labiodentals.

Blasi and his colleagues are not the first to argue this point. The influential linguist Charles Hockett suggested a similar idea in an essay published in 1985. But Hockett's case rested on a particular statement by C. Loring Brace, an influential anthropologist at the University of Michigan. A year after Hockett's trial, Brace responded by telling him that he had changed his mind, which had caused Hockett to reject his own idea.

For decades, Hockett and Brace's round trips have been taken for the last word in this matter. Thus, when Blasi and his colleagues re-examined the issue several years ago, it was for demonstrative purposes. But when the team began to statistically analyze databases of world languages ​​and their distribution, they found a stubborn relationship that they could not explain.

"We tried for months to show that this correlation did not exist (…). We then thought there might be something in there, "says co-author Steven Moran, a linguist at the University of Zurich.

The team then conducted follow-up analyzes, including using a computer model of the bones and facial muscles. Models have shown that it takes about 29% less energy to create labiodentals with overbite than without.

Once F and v The Blasi team explains that sounds became more common, perhaps only inadvertently at first, because the sounds emitted by people who expressed poorly by the touch of the lips, such as p or b, or what linguists call bilabial. But once the labiodentals appeared, they remained around, no doubt because they are usefully distinct. In English, the terms "fever has become global" and "Bieber has become global" have very different meanings.

When the Blasi team compared linguistic records with data on how different companies acquire food, she found that the languages ​​used by modern hunter-gatherers use about a quarter of the time. F This seems to be the case for agricultural societies, suggesting a possible correlation with the diet. And when they examined the vast family of Indo-European languages, they found that the probabilities of labiodental appearing were worse than 50% until 4,000 to 6,000 years ago.

The period of rise of labiodentals is about the beginning when their speakers started using dairy products and growing cereals. The Blasi team argues that it is not a coincidence.

"The soundscape we have is fundamentally affected by the biology of our vocal tract," says co-author of the study, Balthasar Bickel. "It's not just a cultural evolution."

That said, everything from social structures to short-term fashions can also shape language – and the rise of agriculture has led to profound societal changes. Linguists also point out that even within the same population, people's speech can vary widely. (Does geography influence the sound of language?)

The linguist Khalil Iskarous of the University of Southern California, who did not participate in the study, is willing to take into account the probabilistic arguments of the newspaper. But he points out that the organs of human speech do not use much energy compared to movement, and they are so flexible that they can often compensate for differences in bone structure. Sounds made more difficult by overbite, such as the bilabial, can be expected to diminish – but many languages ​​retain them clearly.

Moreover, if energy expenditures really play a driving role in languages, many difficult sounds of language could hardly be adopted. For example, Iskarous highlights clicks that are still an integral part of many Khoisan languages ​​in southern Africa.

"If extremely small efforts have to make the difference between whether or not you have a speech sound, you can predict, for example, that no language should have clicks. And the clicks do not only exist, they spread in many languages ​​that did not have them, "he says. "These are extremely difficult, but it does not matter: there are cultural forces that decided that clicks would spread."

But Blasi continues to insist that his team's claims do not exclude culture.

"The probabilities [for making labiodentals accidentally] are relatively weak, but with a sufficient number of tests – and by that we mean that every statement you make is a single essay – over several generations, this leads to the statistical signal we see, "he says. "But it's not a deterministic process, is it?"

While the researchers continue to debate, the Blasi team has ideas to go next. For example, they say that their methods could help to better reconstruct the way ancient written languages ​​were spoken aloud and thus the endless phonemes of the most beautiful catalog language.