Rethinking where language comes from

A new Science paper challenges the idea that language stems from a single evolutionary root. Instead, it proposes that our ability to communicate evolved through the interaction of biology and culture, and involves multiple capacities, each with different evolutionary histories. The framework unites discoveries across disciplines to explain how the ability to learn to speak, develop grammar, and share meaning converged to create complex communication.

For centuries, philosophers and scientists have wrestled with understanding how human language came about. Language defines us as a species, yet its origins have remained a mystery. In a remarkable international collaboration, ten experts from different disciplines present a unified framework to address this enduring puzzle, harnessing powerful new methods and insights from their respective scientific domains.

“Crucially, our goal was not to come up with our own particular explanation of language evolution,” says first author Inbal Arnon, “Instead, we wanted to show how multifaceted and biocultural perspectives, combined with newly emerging sources of data, can shed new light on old questions.”

Expanding horizons

The authors stress that in the search for language origins, no single explanation is enough. Rather, language arose when different biological abilities - like the capacity to reproduce novel sounds, recognize patterns, and cooperate socially - converged with cultural processes of transmitting knowledge between individuals (both within and across generations).

“The multifaceted nature of language can make it difficult to study, but also expands horizons for understanding its evolutionary origins,” says co-author Simon Fisher. “Rather than looking for that one special thing that singles humans out, we can identify different facets involved in language, and productively study them not just in our own species but also in non-human animals from different branches of the evolutionary tree.”

Importantly, the team highlights how progress has stalled when disciplines worked in isolation from one another. To move forward, they advocate an approach that integrates learning, culture, and biology, drawing on fields as diverse as linguistics, psychology, animal communication, neuroscience and genetics. As one of humanity’s most distinctive traits, language remains a story of connection: between biology and culture, between different scientific fields, and between people themselves.

Three case studies in focus

To demonstrate the power of this framework, the researchers look at three facets whose role in language emergence becomes clearer through a biocultural lens:

1. Vocal Learning: Human speech depends on our ability to learn to reproduce the vocalisations of other speakers. This skill appears to be limited in our closest primate relatives, but has independently emerged elsewhere on the tree of life. For example, some birds, bats, and whales are especially adept at vocal learning. Genetic and behavioural findings on this facet from distantly related species help us understand distinct human capacities.
2. Linguistic Structure: Grammar did not simply appear in our ancestors overnight. Findings from real-life cases of sign language emergence, experiments recreating cultural evolution in the lab, and investigations in songbirds and primates highlight the importance of communication and cultural transmission - being repeatedly used and learned by multiple individuals over generations - in shaping the structure of language. This facet shows how the emergence of structure involves a convergence of biological, cognitive and cultural conditions, in a particular combination that may be unique to humans.
3. Social Foundations: Language is used in interaction with other people. Studies have shown the importance of social interaction for learning human language, and also for other learned communication systems, like birdsong. Added to this, humans have an unusually strong drive to socially share information, which is rarely observed in nonhuman animals.

Biocultural perspectives on language evolution illuminate unique and shared features of the emergence of complex communication, and also pave the way for innovative research on language learning, artificial intelligence, and how communication breaks down in disorders.

The research paper titled “What enables human language? A biocultural framework” will be available in Science after the embargo lifts and can then be accessed at http://www.science.org/doi/10.1126/science.adq8303. More information, including a copy of the paper, can also be found at https://www.eurekalert.org/press/scipak/.