The Origins of Language

For more than 150 years ago, the assumption that language is a singular event has hampered progress in explaining its evolution. Another obstacle was the failure to recognize that certain social interactions, uniquely human interactions, are necessary for the evolution of language.

These problems have been recently remedied by recognizing that words had to evolve before grammar and discovering non-verbal emotional and cognitive relations between an infant and caregiver. As I elaborate below, those relations are known as intersubjectivity and joint attention.

Darwin argued that the theory of evolution could account for the transition from animal communication to language by the principle of natural selection. The idea was that “language differed in degree and not kind” from animal communication. What remained to be discovered was the degree–“innumerable gradations” that separated them.

Some of those gradations have been discovered in recent years. But their nature suggests that language differs in kind from animal communication. With Darwin, Alfred Wallace, who published the first article on the theory of natural selection, wondered how natural selection, which assumes the survival value of a new ability, could account for man’s “superior intelligence.” Compared to apes, Wallace couldn’t understand why natural selection would produce anything more than a slight increment in mental ability. Language, not to mention numerical knowledge or music, is hardly necessary for survival.

Because Wallace assumed that language was a singular event, he didn’t realize that words had to evolve before grammar. If he did, he might have recognized how a theory of the evolution of words would be consistent with the principle of natural selection.

Before words could evolve, some of our ancestors had to become more cooperative than apes. That increment in cooperation was necessary for intersubjectivity and joint attention to evolve. To see how language’s verbal and non-verbal components relate to one another, it is helpful to review why chimpanzees, our nearest living relative, can’t learn language.

Read more: Psychology Today

Bat pups babble and bat moms use baby talk, hinting at the evolution of human language

“Mamama,” “dadada,” “bababa” – parents usually welcome with enthusiasm the sounds of a baby’s babble. Babbling is the first milestone when learning to speak. All typically developing infants babble, no matter which language they’re learning.

Speech, the oral output of language, requires precise control over the lips, tongue and jaw to produce one of the basic speech subunits: the syllable, like “ba,” “da,” “ma.” Babbling is characterized by universal features – for example, repetition of syllables and use of rhythm. It lets an infant practice and playfully learn how to control their vocal apparatus to correctly produce the desired syllables.

More than anything else, language defines human nature. But its evolutionary origins have puzzled scientists for decades. Investigating the biological foundations of language across species – as I do in bats – is a promising way to gain insights into key features of human language.

I’m a behavioral biologist who has spent many months of 10-hour days sitting in front of bat colonies in Panama and Costa Rica recording the animals’ vocalizations. My colleagues and I have found striking parallels between the babbling produced by these bat pups and that by human infants. Identifying a mammal that shares similar brain structure with human beings and is also capable of vocal imitation may help us understand the cognitive and neuromolecular foundations of vocal learning.

Vocal learning in other animals

Scientists learned a great deal about vocal imitation and vocal development by studying songbirds. They are among the best-known vocal learners, and the learning process of young male songbirds shows interesting parallels to human speech development. Young male songbirds also practice their notes in a practice phase reminiscent of human infant babbling.

However, songbirds and people possess different vocal apparatus – birds vocalize by using a syrinx, humans use a larynx – and their brain architecture differs. So drawing direct conclusions from songbird research for humans is limited.

Luckily, in Central America’s tropical jungle, there’s a mammal that engages in a very conspicuous vocal practice behavior that is strongly reminiscent of human infant babbling: the neotropical greater sac-winged bat, Saccopteryx bilineata. The pups of this small bat, dark-furred with two prominent white wavy stripes on the back, engage in daily babbling behavior during large parts of their development.

Read more: The Conversation

Can these birds explain how language first evolved?

If you want a no-fuss, no-muss pet, consider the Bengalese finch. Dubbed the society finch for its friendliness, breeders often use it to foster unrelated chicks. But put the piebald songbird next to its wild ancestor, the white-rumped munia, and you can both see and hear the differences: The aggressive munia tends to be darker and whistles a scratchy, off-kilter tune, whereas the pet finch warbles a melody so complex that even nonmusicians may wonder how this caged bird learned to sing.

All this makes the domesticated and wild birds a perfect natural experiment to help explore an upstart proposal about human evolution: that the building blocks of language are a byproduct of brain alterations that arose when natural selection favored cooperation among early humans. According to this hypothesis, skills such as learning complex calls, combining vocalizations, and simply knowing when another creature wants to communicate all came about as a consequence of pro-social traits like kindness. If so, domesticated animals, which are bred to be good-natured, might exhibit such communication skills too.

The idea is rooted in a much older one: that humans tamed themselves. This self-domestication hypothesis, which got its start with Charles Darwin, says that when early humans started to prefer cooperative friends and mates to aggressive ones, they essentially domesticated themselves. Along with tameness came evolutionary changes seen in other domesticated mammals—smoother brows, shorter faces, and more feminized features—thanks in part to lower levels of circulating androgens (such as testosterone) that tend to promote aggression.

Higher levels of neurohormones such as serotonin were also part of the domestication package. Such pro-social hormones help us infer others’ mental states, learn through joint attention, and even link objects and labels—all prerequisites for language, says developmental psychologist Michael Tomasello of Duke University in Durham, North Carolina, who studies social cognition.

In recent papers and at Evolang, a biannual conference on language evolution held here this spring, researchers turned to birds, foxes, and bonobos to help understand how domestication may have paved the way for language. Constantina Theofanopoulou, a neuroscientist at the University of Barcelona in Spain who convened the Evolang workshop, calls it the “most promising” working hypothesis to account for the thorny problem of language evolution, because it “puts together evidence from different levels of biological analysis: the anatomical, the brain, the endocrine system, and behavior.”

Read more: Science

The Randomness of Language Evolution

Joshua Plotkin’s dive into the evolution of language began with clarity—and also a lack of it.

Today, if you wanted to talk about something that’s clear, you’d say that it has clarity. But if you were around in 1890, you would almost certainly have talked about its clearness.

Plotkin first noticed this linguistic change while playing with Google’s Ngram Viewer, a search engine that charts the frequencies of words across millions of books. The viewer shows that a century ago, clearness dominated clarity. Now the opposite is true, which is strange because clarity isn’t even a regular form. If you wanted to create a noun from clear, clearness would be a more obvious choice. “Why would there be this big upswing in clarity?,” Plotkin wondered. “Is there a force promoting clarity in writing?”

It wasn’t clear. But as an evolutionary biologist, Plotkin knew how to find out.

The histories of linguistics and evolutionary biology have been braided together for as long as the latter has existed. Many of the earliest defenders of Darwinism were linguists who saw similarities between the evolution of languages and of species. Darwin himself wrote about these “curious parallels” in The Descent of Man. New words and grammatical rules are continually cropping up, fighting for existence against established forms, and sometimes driving those old forms extinct. “The survival … of certain favored words in the struggle for existence is natural selection,” Darwin wrote.

Read more: The Atlantic

These Scientists Think Local Climates Shaped the Evolution of Language

The thatched roof held back the sun’s rays, but it could not keep the tropical heat at bay. As everyone at the research workshop headed outside for a break, small groups splintered off to gather in the shade of coconut trees and enjoy a breeze. I wandered from group to group, joining in the discussions. Each time, I noticed that the language of the conversation would change from an indigenous language to something they knew I could understand, Bislama or English. I was amazed by the ease with which the meeting’s participants switched between languages, but I was even more astonished by the number of different indigenous languages.

Thirty people had gathered for the workshop on this island in the South Pacific, and all except for me came from the island, called Makelua, in the nation of Vanuatu. They lived in 16 different communities and spoke 16 distinct languages.

In many cases, you could stand at the edge of one village and see the outskirts of the next community. Yet the residents of each village spoke completely different languages. According to recent work by my colleagues at the Max Planck Institute for the Science of Human History, this island, just 100 kilometers long and 20 kilometers wide, is home to speakers of perhaps 40 different indigenous languages. Why so many?

We could ask this same question of the entire globe. People don’t speak one universal language, or even a handful. Instead, today our species collectively speaks over 7,000 distinct languages.

Read more: Inverse

What the Evolution of Language in Humans Means for AI

In his new book, Agreement Beyond Phi, MIT linguist Shigeru Miyagawa explores the concept of universal languages by analyzing similarities between a range of languages.

This is a topic in linguistics that gives a fresh take on the science of words and their construction, and Miyagawa is hopeful that his research and analysis will allow him to apply his theory to more languages out of the Indo-European spectrum.

In his book, he makes the argument that all languages have allocutive agreement, which is defined as “a morphological feature in which the gender of an addressee is marked overtly in an utterance using fully grammaticalized markers.”

For the non-linguists out there, it’s kind of like a form of subject-verb agreement that allows for formality to change the way that a verb is spoken. When speaking French, for example, to say to friend that “he has” something would be “tu as” but for a professor, or doctor, the polite version would be “vous avez.”

This is notable in Basque, as well as Japanese, which has a certain method of “politeness making.” In the book, he details the similarities between languages like French, English, Basque, Japanese, Dinka, and Jingpo, but he would like to continue exploring further.

Read more: Edgy Labs

Stanford research explores novel perspectives on the evolution of Spanish

How has the Spanish language evolved in the hundreds of years it has been spoken on multiple continents?

To answer the question, Cuauhtémoc García-García, a graduate student in Iberian and Latin American cultures, analyzed 900 years’ worth of texts in over a quarter of a million volumes.

“I wanted to study language evolution through data found in written work to add historical depth to how, where and when languages changed,” he said. “My new data show that Spanish on the Iberian Peninsula was much more resistant to change over time when compared to Spanish in the Americas, where – since colonization – Spanish from Spain has come into contact with local, indigenous and hybrid influences.”

That process, he noted, has led to a Spanish that has progressively changed ever since the language first arrived in the Americas. The changes, however, are not uniform across the Spanish-speaking Americas, and instead he found that the “hybridization” and evolution of language varied from place to place.

Read more: Stanford University

Mice’s love songs go wrong when ‘language gene’ is messed up

Mouse squeaks may have more in common with human speech than we realised. Tinkering with a gene associated with language in humans has been found to mess up mice’s mating calls.

The gene, called FOXP2, is one of the most-studied genes involved in human brain evolution. It was discovered in the 1990s in a study of a British family that had 16 relatives who had difficulty making certain mouth movements and complex sounds.

The gene turned out to encode a protein that is found in the brain while we develop in the womb, and its shape suggests it works by helping to turn other genes on and off. Other studies have shown that, while FOXP2 has stayed mostly unchanged throughout mammal evolution, there have been two mutations in the gene since we split from our closest living relatives, chimpanzees.

It is thought that these mutations enabled us to evolve superior vocal abilities. But the mutation seen in the original family is different, and it is not known how exactly it affects speech. Putting this mutated gene into mice helps us unravel what has gone wrong, and might let us understand other genetic speech disorders, says Simon Fisher at the Max Planck Institute for Psycholinguistics in Nijmegen in The Netherlands.

Read more: New Scientist