Toddlers build on what they know to learn new words

New research about how toddlers learn new words underscores that the amount of language a child hears on a daily basis can have significant consequences on their language outcomes later in life, Brock Ferguson says. (Credit: Tom Conger/Flickr)

Even before young children begin to talk in sentences, they can use words they already know to learn new ones they don’t.

By 19 months of age, children pay careful attention to the way a new word is used in conversation, a new study shows.

For example, if you take a toddler to the zoo and say, “Look at the gorilla” while pointing at the cage, the infant may not know exactly to what you are referring. However, if you say, “Look! The gorilla is eating,” the child can use the word that they do know—”eating”—to  conclude that “gorilla” must refer to the animal and not, for example, the swing it’s sitting on.


The zoo scenario mirrors the method researchers used in their experiment. First, children at ages 15 and 19 months were shown several pairs of pictures on a large screen. Each pair included one new kind of animal and a non-living object.

Next, the objects disappeared from view and the children overheard a conversation that included a new word, “blick.” Finally, the two objects re-appeared, and infants heard, for example, “Look at the blick.”

“After overhearing this new word in conversation, infants who hear a helpful sentence such as ‘the blick is eating’ should look more towards the animal than the other, non-living object,” says Brock Ferguson, a doctoral candidate in psychology at Northwestern University and lead author of the study.

“We show that by 19 months, they do just that. In contrast, if infants heard the new word in an unhelpful sentence such as ‘the blick is over here’ during the conversation, they don’t focus specifically on the animal because, after all, in this kind of sentence, ‘blick’ could mean anything.”

Attuned to conversation

The researchers say many people believe that word learning occurs only in clear teaching conditions. For example, when someone picks up an object, brings it to the child, points to it, and says its name. In fact, toddlers usually hear a new word for the first time under much more natural and complex circumstances such as the zoo example described.

“What’s remarkable is that infants learned so much from hearing the conversation alone,” says senior author Sandra Waxman, professor of psychology. “This shows how attuned even very young infants are to the conversation around them. It also shows how well infants build upon what they do know to build their vocabulary.”

Published in the journal Cognition, the study underscores that the amount of language a child hears on a daily basis can have significant consequences on their language outcomes later in life, Ferguson says.

“One implication of our new study is that infants who hear relatively little language in the first few years may also be missing out on critical word learning opportunities that arise everyday in the conversations that surround them.”

Future research will include examining the link between language input, processing efficiency, and the kind of word learning revealed in the study to better understand how to best support children’s language development from a very early age.

Eileen Graf of the University of Chicago is also a co-author of the article.

Source: Northwestern University