AS THE SAYING goes, we are what we eat—but does that aspect of our identity carry over to the languages we speak?
In a new study in Science, a team of linguists at the University of Zurich uses biomechanics and linguistic evidence to make the case that the rise of agriculture thousands of years ago increased the odds that populations would start to use sounds such as f and v. The idea is that agriculture introduced a range of softer foods into human diets, which altered how humans’ teeth and jaws wore down with age in ways that made these sounds slightly easier to produce.
“I hope our study will trigger a wider discussion on the fact that at least some aspects of language and speech—and I insist, some—need to be treated as we treat other complex human behaviors: laying between biology and culture,” says lead study author Damián Blasi.
If confirmed, the study would be among the first to show that a culturally induced change in human biology altered the arc of global languages. Blasi and his colleagues stress that changes in tooth wear didn’t guarantee changes in language, nor did they replace any other forces. Instead, they argue that the shift in tooth wear improved the odds of sounds such as f and v emerging. Some scientists in other fields, such as experts in tooth wear, are open to the idea. (Today, many scientists are racing to save languages that are dying out.)
“[Tooth wear] is a common pattern with deep evolutionary roots; it’s not specific for humans [and] hominins but also present in the great apes,” University of Zurich paleoanthropologists Marcia Ponce de León and Christoph Zollikofer, who didn’t participate in the study, say in a joint email. “Who could have imagined that, after millions of years of evolution, it will have implications for human language diversity?” (Another study shows how ancient cave art may be linked to language.)
While the study relies on various assumptions, “I think the authors build a very plausible case,” adds Tecumseh Fitch, an expert on bioacoustics at the University of Vienna who wasn’t involved with the work. “This is probably the most convincing study yet showing how biological constraints on language change could themselves change over time due to cultural changes.”
But many linguists have defaulted to skepticism, out of a broader concern about tracing differences in languages back to differences in biology—a line of thinking within the field that has led to ethnocentrism or worse. Based on the world’s huge variety of tongues and dialects, most linguists now think that we all broadly share the same biological tools and sound-making abilities for spoken languages.
“We really need to know that the small [average] differences observed in studies like this aren’t swamped by the ordinary diversity within a community,” Adam Albright, a linguist at MIT who wasn’t involved with the study, says in an email.
Read more: National Geographic