Words Help Infants Categorize Objects, Key to Learning

January 2, 2013

by Robin Tricoles

Infants have a well-earned reputation for spending their days sleeping, eating, and crying. But in reality, they’re up to much more. And doing it much earlier than previously thought. Babies are busy developing their cognitive acumen through language acquisition long before they learn to stand, walk, or talk.

Sandra Waxman is an expert on how language affects infants’ cognitive development, specifically, the way it influences infants’ ability to form object categories. For instance, babies appreciate the commonalities among different dogs even though dogs are distinct from one another in many ways, including size, shape, and color.

Waxman’s work shows that infants also appreciate object categories that are even more abstract. “But even more importantly babies eventually come to know a dog, and a horse, and a duck, and a fish are all animals even though they look wickedly different from one another,” says Waxman. “The human cognitive system notices commonalities early on. And this ability is important because noticing commonalities is the first step to categorizing objects and experiences.”

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In fact, it’s a key component of learning. Waxman’s recent research shows that words help infants focus on the similarities among objects, similarities that would have gone unnoticed had a word for them not been communicated to the infant. 

For example, Waxman shows babies a series of objects (say, a dog, a horse, and other animals). What she varies is what babies hear as they see these objects.  If the objects are all introduced with the same name, babies form a category “animal”. But if the objects are introduced instead with tone sequences, they do not form the category.  This shows the powerful ad surprisingly early link between human language and human thought.

“At 12, 9, 6 and even 3 months, infants were able to form an object categorization with the words but not with the tone,” says Waxman. “And that’s amazing, because a six-month-old is just beginning to pull individual words from the ongoing sound stream. They’re beginning to get individual words, but it’s not a skill that they’ve mastered. Words help infants focus on aspects of their world that they otherwise would take much longer to learn about.”

Waxman is now working on a series of studies that aim to explain this early link between language and categories. Her question: Is language unique in its ability to support infant cognition?


Sandra R. Waxman, PhD, is a professor of cognitive psychology at Northwestern University. Her research focuses on language and conceptual development in infancy and early childhood; cross-linguistic and cross-cultural perspectives; and early acquisition of concepts, words, and inductive reasoning. Waxman is a fellow of the American Association for the Advancement of Science and the American Psychological Association.

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