Dogs can extend word meanings to new objects based on function, not appearance
Dogs with a vocabulary of toy names—known as Gifted Word Learners—can extend learned labels to entirely new objects, not because the objects look similar, but because they are used in the same way.
Eötvös Loránd University
image:
A new study publishing in Current Biology on September 18 reveals that dogs with a vocabulary of toy names—known as Gifted Word Learners—can extend learned labels to entirely new objects, not because the objects look similar, but because they are used in the same way.
view moreCredit: Department of Ethology / Eötvös Loránd University
BUDAPEST, Hungary — A new study publishing in Current Biology on September 18 by the Department of Ethology at Eötvös Loránd University reveals that dogs with a vocabulary of toy names—known as Gifted Word Learners—can extend learned labels to entirely new objects, not because the objects look similar, but because they are used in the same way.
In humans, “label extension” is a cornerstone of early language development. In non-humans, until now, it had only been documented in few so-called language-trained individual animals, after years of intensive training in captivity.
But learning to extend labels to objects that share the same function, rather than visual similarities, is considered an even more complex skill. A toddler learns that the word “cup” can apply to mugs, tumblers, and sippy cups, or that both a spoon and a ladle are “for scooping.” While individuals of many animal species can group items by appearance, extending a learned label to a functionally similar but visually different object has long been considered an advanced skill.
The time and efforts needed to train animals in captivity to learn verbal labels, as well as the very limited number of subjects that successfully acquired such vocabulary, have until now limited the feasibility of this type of research.
But here comes the twist! “Gifted Word Learner dogs offer a unique possibility to study this phenomenon because they rapidly learn verbal labels – the names of toys – during natural interactions in their human families” said Dr. Claudia Fugazza, lead author of the study.
“Our results show that these dogs do not just memorize object names,” continues Dr. Fugazza. “They understand the meaning behind those labels well enough to apply them to new, very different-looking toys— by recognizing what the toys were for.”
A Play-Based Experiment
Researchers of the Department of Ethology, at Eötvös Lorand University tested 7 Gifted Word Learner dogs—(six Border collies and a Blue heeler)—known for their unusual ability to learn the names of dozens of toys naturally, through everyday play.
The experiment had four stages, all of them conducted in a natural setup, at the house of each dog owner, during playful interactions:
- Fist, in the Learning Phase, Dogs learned two new labels, such as “Pull” and “Fetch,” each referring not to a single item, but to a group of toys that looked completely different but were used in the same way during play (tug or retrieve).
- Second, during a formal Assessment, the dogs showed that they had successfully learned those labels and could appropriately choose the “Pulls” and “Fetches” when asked.
- The crucial part of the experiment was carried out after this Assessment: in the Generalization Phase, the dogs were introduced to new toys, also with diverse physical features, and the owner played in the same two ways as before, but this time saying no labels.
- Test – When asked for a “Pull” or “Fetch,” the dogs selected the correct unlabelled toy significantly above chance, indicating they had generalized the labels to a functional category.
Why This Matters
The study provides the first evidence that dogs can generalize verbal labels to functional categories during natural-like playful interactions in their human families—mirroring, in functional terms, the natural context of human language development.
“This ability shows that classification linked to verbal labels can emerge in non-human, non-linguistic species living in natural settings,” said Dr. Adam Miklosi, coauthor of the study. “It opens exciting new avenues for studying how language-related skills may evolve and function beyond our own species.”
Key Points
- Dogs extended verbal labels to objects that shared only functional properties, not appearance.
- The skill emerged naturally through play with owners—no formal training required.
- While the mechanisms of such learning are not known, the context in which it happens present a striking parallel with that of human infants: daily life in a human family.
- The study of these skills in a non-human species in its natural environment paves the way for understanding the how language-related skills evolved and function.
Journal
Current Biology
Article Title
Dogs extend verbal labels for functional classification of objects
Article Publication Date
18-Sep-2025
With no prior training, dogs can infer how similar types of toys work, even when they don’t look alike
Cell Press
image:
Gaia with a pile of toys
view moreCredit: Claudia Fugazza
As infants, humans naturally learn new words and their associations—like the fact that forks are related to bowls because both are used to consume food. In a study publishing in the Cell Press journal Current Biology on September 18, a team of animal behavior experts demonstrate that dogs can categorize objects by function, too. In a series of playful interactions with their owners, a group of Gifted Word Learner (GWL) dogs were able to distinguish between toys used for tugging versus fetching, even when the toys in question didn’t share any obvious physical similarities—and then could remember those categorizations for long periods of time, all with no prior training.
“We discovered that these Gifted Word Learner dogs can extend labels to items that have the same function or that are used in the same way,” says author Claudia Fugazza (@geniusdogchallenge) of Eötvös Loránd University, Budapest, Hungary. It’s like a person calling both a traditional hammer and a rock by the same name, says Fugazza.
“The rock and the hammer look physically different, but they can be used for the same function,” she says. “So now it turns out that these dogs can do the same.”
The studies took place in the dogs’ natural home environments with their human owners. At the beginning, the dogs spent time getting familiar with verbal labels for two functional groups of objects: pull and fetch. Their owners used these words with specific toys and played with them accordingly even though the toys didn’t share any similar physical features.
Next, the dogs were tested to see if they had learned to connect the functional labels to the correct group of toys before playing with more novel toys in the two distinct categories. However, this time, their owners didn’t use the “pull” and “fetch” labels for the dogs.
The team found that the dogs were able to extend the functional labels they’d learned previously to the new toys based on their experience playing with them. In the final test, the dogs showed that they could successfully apply the verbal labels to the toys by either pulling or fetching accordingly, even when their owners hadn’t named them.
“For these new toys, they’ve never heard the name, but they have played either pull or fetch, and so the dog has to choose which toy was used to play which game,” Fugazza says. “This was done in a natural setup, with no extensive training. It's just owners playing for a week with the toys. So, it’s a natural type of interaction.”
The authors note that the dogs’ ability to connect verbal labels to objects based on their functional classifications and apart from the toys’ physical attributes suggests that they form a mental representation of the objects based on their experience with their functions, which they can later recall. These findings provide insight into the evolution of basic skills related to language and their relationship to other cognitive abilities, including memory, the researchers say.
More research is needed to understand the scope and flexibility of dogs’ language categorization abilities. The researchers suggest future studies to explore whether dogs that don’t learn object labels may nevertheless have an ability to classify objects based on their functions.
“We have shown that dogs learn object labels really fast, and they remember them for a long period, even without rehearsing,” Fugazza says. “And I think the way they extend labels also beyond perceptual similarities gives an idea of the breadth of what these labels could be for dogs.”
###
This work was supported by National Brain Research Program NAP 3.0 of the Hungarian Academy of Sciences, MTA-ELTE Comparative Ethology Research Group, and TRIXIE.
Current Biology, Fugazza et al. “Dogs extend verbal labels for functional classification of objects” https://www.cell.com/current-biology/fulltext/S0960-9822(25)01079-6
Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit: http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.
Journal
Current Biology
Method of Research
Experimental study
Subject of Research
Animals
Article Title
Dogs extend verbal labels for functional classification of objects
Article Publication Date
18-Sep-2025
