The University of Cagliari is also among the protagonists of a large international study published in Science Advances and coordinated by the University of Zurich. The research linked genetic data from over 4,700 individuals from 558 populations with linguistic information on thousands of languages , to understand how contact between communities influenced the evolution of language.

When populations meet, in fact, they exchange not only genes but also words, sounds, and ways of speaking. The study demonstrates on a global scale that human contact can lead to the passage of linguistic elements from one language to another: sounds, terms, or grammatical structures. A phenomenon exemplified by loanwords from Italian—such as "pizza" or "adagio"—which have spread throughout the world, or the word "tsunami," which entered our language from Japanese.

The most striking finding is that, almost everywhere in the world, when two populations come into contact, their languages tend to become more similar, albeit in different ways. The probability of language sharing, the researchers explain, increases on average from 4 to 9% between unrelated languages. "We were struck by how remarkably consistent this effect is, both in the most ancient contacts—such as those linked to Neolithic migrations—and in the more recent ones, linked to colonization or globalization," says Chiara Barbieri, a population geneticist and professor at the University of Cagliari's Department of Life and Environmental Sciences, and one of the study's senior authors . "In both cases, we see that languages reflect the demographic history of peoples, becoming more similar when they meet."

"Not all linguistic characteristics are transmitted equally easily: some, like word order or certain sounds, are more 'predictable'; others much less so. But there are also those who take the opposite direction: in certain contexts, groups choose to differentiate their languages to mark distinct identities." Although contact tends to make languages converge, it sometimes leads them to diverge," explains linguist Anna Graff, first author of the study. The study opens new perspectives not only for understanding the history of the world's languages, but also for reflecting on what lies ahead. While on the one hand, contact enriches and brings us closer, on the other, it can erode linguistic diversity. In an era marked by globalization, migration, and climate change, these dynamics risk intensifying. "Understanding the links between genes and languages means better understanding the history of humanity," concludes Barbieri, "and helps us interpret the changes underway in today's society."