Humans are unique in their ability to acquire language. But how? A new study published in the Proceeding of the National Academy of Sciences shows that we are in fact born with the basic fundamental knowledge of language, thus shedding light on the age-old linguistic "nature vs. nurture" debate.

While languages differ from each other in many ways, certain aspects appear to be shared across languages. These aspects might stem from linguistic principles that are active in all human brains. A natural question then arises: are infants born with knowledge of how the human words might sound like? Are infants biased to consider certain sound sequences as more word-like than others?

BLA, ShBA, LBA

Consider, for instance, the sound-combinations that occur at the beginning of words. While many languages have words that begin by bl (e.g., blando in Italian, blink in English, and blusa in Spanish), few languages have words that begin with lb. Russian is such a language (e.g., lbu, a word related to lob, "forehead"), but even in Russian such words are extremely rare and outnumbered by words starting with bl.

Linguists have suggested that such patterns occur because human brains are biased to favor syllables such as bla over lba. In line with this possibility, past experimental research has shown that adult speakers display such preferences, even if their native language has no words resembling either bla or lba. But where does this knowledge stem from? Is it due to some universal linguistic principle, or to adults' lifelong experience with listening and producing their native language?

These questions motivated the team to look carefully at how young babies perceive different types of words. They used near-infrared spectroscopy, a silent and non-invasive technique that tells them how the oxygenation of the brain cortex (those very first centimeters of gray matter just below the scalp) changes in time, to look at the brain reactions of Italian newborn babies when listening to good and bad word candidates as described above (e.g., blif, lbif). 

Working with Italian newborn infants and their families, they observed that newborns react differently to good and bad word candidates, similar to what adults do. Young infants have not learned any words yet, they do not even babble yet, and still they share with us a sense of how words should sound. This finding implied that we are born with the basic, foundational knowledge about the sound pattern of human languages. 

"The results of this new study suggest that, the sound patterns of human languages are the product of an inborn biological instinct, very much like birdsong" said Prof. Iris Berent of Northeastern University in Boston, who co-authored the study with a research team from the International School of Advanced Studies in Italy, headed by Dr. Jacques Mehler. The study's first author is Dr. David Gómez.

It is hard to imagine how differently languages would sound if humans did not share such type of knowledge. We are fortunate that we do, and so babies can come to the world with the certainty that they will readily recognize the sound patterns of words - no matter the language they will grow up with.