Domestic dogs respond to 89 words and phrases, on average â including verbs, nouns and terms of endearment â suggesting that their human vocabulary skills extend well beyond intentional cues like âsitâ and âstayâ.
and Catherine Reeve at Dalhousie University in Canada created an initial inventory of 172 words and phrases they suspected pet and working dogs might be most likely to recognise. That list was based on prior studies, dog training courses, items marketed for dogs in pet shops, places dogs often go, their own experiences with dogs and recommendations from a group of dog owners.
Then, the pair collected information from 165 dog owners responding to their online questionnaire, shared mainly via social media. The survey asked owners to rate how well their dogs consistently and clearly responded to the English words and phrases on the list.
Advertisement
By ârespondingâ, the researchers meant not only performing a trick or obedience behaviour, says Jacques, but any other specific reaction like enthusiastic tail wagging, a directed gaze or searching around. They also asked participants to suggest additional relevant terms not included on the list.
On average, the owners reported that their dogs responded to 78 items on the original list as well as 11 owner-added terms, meaning the average dog responded to 89 words or phrases.
The list of expressions in the current study probably helped trigger ownersâ memories of words their dogs recognised and inspired them to think of others, says Jacques. In total, owners added around 1000 unique words to the researchersâ list based on their own dogsâ experiences.
Individually, dogsâ vocabulary levels ranged from 15 to 215 words and phrases, three times more than shown in . The repertoire comprises words and expressions the animals probably learned incidentally through living with humans, such as âoutsideâ, âdinnerâ, âvetâ, âwhoâs that?â, âI love youâ, room names and the names of family members and other pets, says Jacques.
âWe were very careful not to ask if the dogs know, or understand, words, but if they respond to words,â says Jacques. âIf any owner uses the same words over and over again, in a predictable context, their dogs might start picking up on those words [perhaps without the owner even realising it].â
While the researchers didnât investigate differences between individual breeds, they did note trends among seven major breed categories. In particular, herding dogs â collies and shepherds â and toy-companion breeds, such as Chihuahuas and poodles, averaged slightly over 112 words. Meanwhile, sporting and gun dogs â mainly spaniels and retrievers â responded to an average of about 80 words.
âThe higher numbers of words for herding and shepherd dogs wasnât surprising because thatâs what these dogs were bred to do, to interact with humans,â says Jacques. âAnd toy dogs are bred to be human companions and spend a lot of time close to humans, so that makes sense as well.â
The dogsâ working status was also related, she says, with those professionally trained for working with humans, such as service dogs, responding to about 48 per cent more terms than those that arenât.
Characteristics of the dogsâ owners, however, didnât influence the results, says Jacques. There was no link between a personâs level of education, household income or experience as a dog trainer and the total number of terms their dogs responded to.
âThe next step is to see whether or not this predicts anything about the dogs, like cognitive skills, later word knowledge or other capacities,â she says. âAnd if so, this might become a really important tool for identifying potential service dogs in particular.â
Applied Animal Behaviour Science
Sign up to Wild Wild Life, a free monthly newsletter celebrating the diversity and science of animals, plants and Earthâs other weird and wonderful inhabitants
