Your child is an advanced language learner

A new study from the MIT Language Acquisition Laboratory offers a new perspective on the subject: Sentences contain subtle clues in the grammar that tell young children about the meaning of new words. The finding, based on experiments with 2-year-old children, shows that even very young children can absorb grammatical cues in language and use this information to acquire new words.

“Even at a surprisingly young age, children have an advanced knowledge of the grammar of sentences and can use this to learn the meanings of new words,” says Athulya Aravind, an associate professor of linguistics at MIT.

The new understanding contrasts with the previous explanation of how children build their vocabulary: they rely on the concept of “reciprocal exclusivity”, that is, they treat each new word as if it corresponded to a new object or category. Instead, the new research shows how comprehensively children respond directly to grammatical information when interpreting words.

“For us, this is very exciting because it’s a very simple idea that explains a lot about how children understand language,” says Gabor Brody, first author of the paper and a postdoctoral researcher at Brown University.

The article was titled: “Why Do Children Think Words Are Mutually Exclusive?” It is published in advance online format. Psychological Science. Writers are Brody; Roman Feiman, Thomas J. and Alice M. Tisch Assistant Professor of Cognitive and Psychological Sciences and Linguistics at Brown; and Aravind, the Alfred Henry and Jean Morrison Hayes Career Development Associate Professor in MIT’s Department of Linguistics and Philosophy.

focus on focus

Many scientists think that young children have an innate bias toward mutual exclusivity when learning new words, which may explain how children learn some of the new words. However, the concept of mutual exclusivity has never been airtight: While words like “bat” refer to more than one type of object, any given object can be described using a countless number of words. For example, a rabbit may be called not only “rabbit” or “bunny” but also “animal” or “beauty” and even “delicacy” in some contexts. Despite the lack of a perfect one-to-one mapping between words and objects, mutual exclusivity is still suggested as a strong tendency in children’s word learning.

What Aravind, Brody, and Fieman suggest is that children have no such tendency and instead rely on “focus” signals to decide what a new word means. Linguists use the term “focus” to refer to the way we stress or highlight certain words to signal some kind of contrast. Depending on what is focused on, the same sentence can have different effects. “Carlos give Lewis a Ferrari” implies the contrast with other possible cars — he could have given Lewis a Mercedes. But “Carlos did Lewis “Ferrari” implies contrast with other people; He could give Alexandra a Ferrari.

The researchers’ experiments manipulated focus in three experiments with a total of 106 children. Participants watched videos of a cartoon fox that asked them to point to different objects.

The first experiment revealed how focal point affects children’s choice between two objects that, when they hear a label like “toy,” could in principle correspond to either of them. After naming one of the two objects (“Look, I’m pointing at the fence”), the fox said to the child, “Now you’re pointing at the toy!” The children were divided into two groups. One group heard the word “toy” without emphasizing it, while the other group heard it with emphasis.

In the first version, “blicket” and “toy” plausibly refer to the same object. In the second version, however, the added focus through intonation implies that “toy” contrasts with the “blicket” discussed earlier. Without focus, only 24 percent of respondents thought the words were mutually exclusive, while with focus created by emphasizing “toy,” 89 percent of respondents thought “blicket” and “toy” referred to different objects.

The second and third experiments showed that focus is not only important when it comes to words like “toy” but also affects the interpretation of new words that children have never encountered before, such as “wug” or “dax.” When a new word was said without focusing, children 71 percent thought that this word meant the object named before. But when they heard the new word spoken with focus, 87 percent of them thought it must refer to a new object.

“Even though they knew nothing about this new word, it still told them something when they focused on it: Focusing communicated to the children the existence of a contrasting alternative, and accordingly they understood that the noun referred to a previously unlabeled object,” explains Aravind.

He adds: “The specific claim we’re making is that there’s no innate bias for reciprocal exclusivity in children. The only reason we make the corresponding inference is because focus tells you that the word means something different than another word. When the focus goes away, kids don’t make these reciprocal inferences anymore.”

The researchers believe that the overall experiments shed new light on the subject.

“Earlier explanations of mutual exclusivity introduced a completely new problem,” says Feiman. “If children assume that words are mutually exclusive, how will they learn words that aren’t? After all, you can call the same animal a bunny or a bunny, and children have to learn both at some point. Our finding explains why this isn’t actually a problem. Children can learn words that are not, as long as adults don’t tell them so.” By default it does not think that the new word is mutually exclusive with the old word; if the new word is not mutually exclusive, all adults need to do this without focusing and think it is compatible if they will do it naturally.

learning language from language

The researchers note that the experiment is the result of interdisciplinary research that bridges psychology and linguistics; in this case, it mobilizes the focal concept of linguistics to address a topic that concerns both fields.

“We hope this will be a paper that shows that small, simple theories have a place in psychology,” says Brody. “It’s a very small theory, not a very big model of the mind, but it completely flips the switch on some of the phenomena we thought we understood.”

If the new hypothesis is correct, researchers may have developed a more robust explanation for how children use new words correctly.

“An effective idea in language development is that children can use their existing language knowledge to learn more languages,” says Aravind. “We kind of build on this idea and say that even in the simplest situations, aspects of language that children already know, in this case focus understanding, help them grasp the meaning of unknown words.”

Academics agree that further study could further improve our knowledge on the subject. In the paper, they note that future research could re-examine previous studies on reciprocal exclusivity, recording and examining natural interactions between parents and children to see how focal point is used, and examining the issue in other languages, especially languages ​​that mark focal point in alternative ways. in word order.

The research was supported in part by a Jacobs Foundation Fellowship awarded to Feiman.