Researchers have long wondered why certain fundamental characteristics of grammar are present in all languages, and now a team of scientists at the University of Rochester has found evidence that these properties are built into the way our brains work. The report, recently published in the Proceedings of the National Academy of Sciences, examines deaf individuals who have been isolated from conventional sign, spoken, and written language their entire lives, and yet still developed a unique form of gesture communication.
"Our findings suggest that certain fundamental characteristics of human language systems appear in gestural communication, even when the user has never been exposed to linguistic input and has not descended from previous generations of skilled communicative partners," says Elissa L. Newport, George Eastman Professor of Brain and Cognitive Sciences and Linguistics at the University of Rochester. "We examined a particular hallmark of known grammatical systems and found that these signers also used this same hallmark in their gestured sentences. They designed their own language and wound up with some of the same rules of grammar every other language uses."
For eight years, Newport and Marie Coppola, a post-doctoral student at the University of Chicago, studied three deaf Nicaraguan boys who had no exposure to any sign formal language. They were linguistically separated from spoken language by virtue of their complete deafness since birth; separated from knowledge of Nicaraguan Sign Language because they'd never had contact with another signer; and separated from written Spanish since they had little or no formal education. This isolation forced each of the three boys to develop their own gestural-based language, called 'home sign systems' in the field of sign language research. These three isolated languages gave Coppola and Newport a window into how the brain creates language.
The home signers watched 66 very short videos consisting of single actions, such as a woman walking or a man smelling flowers. Using their home sign, they explained what they had seen. All three home signers consistently used the grammatical construction of "subject" in the same form it is used throughout languages around the world.
The concept of "subject" is ubiquitous in language, but is complex and difficult to define. Language assigns concepts to symbols, but does so imperfectly—a noun is usually an object, but certainly not always, as the noun "liberty" demonstrates. A prominent example of this abstract property of language is the idea of subject. While grammar school teachers might explain that a subject is the person, place or thing that performs the action in the sentence, in fact subjects are not necessarily the one who produces or instigates an action.
For instance, in the sentence, "John opened the door," the subject is "John"; but in "The door opened," the word "door" has become the subject, and in "John got hit," the word "John" is the subject even though he is the recipient of the action. Despite having to essentially design their own languages without influence from any other speakers or signers of an established language, the home signers created a complex grammatical component and used it in the same way highly evolved languages do. That the idea of "subject" exists in these individuals and is used in the same manner, strongly suggests that this basic and somewhat arbitrary property of language is an innate tendency in humans as they develop any communication system.
"The notion of 'subject' does not appear to require either linguistic input or a lengthy history within a language to develop," says Newport. "We're starting to see that the grammatical concept of 'subject' is part of the bedrock on which languages form."
Newport is continuing her research into other aspects of linguistics to see what else may be innate in human language, and also how language input alters and expands these innate tendencies. Her past research in cognitive science settled a once-controversial question about whether there are crucial periods in children's development when they are primed to learn languages. Newport found that there is a distinct curve showing that fluent language skills arise when a child is exposed to the language very early, but the ability to learn a language declines thereafter.