By Amarachi Orie, CNN
(CNN) — Toddlers can pick up new words just by overhearing conversations. Now, new research suggests that some intelligent dogs can expand their vocabulary in just the same way.
Children as young as 18 months old can learn labels for objects by listening to other people’s exchanges, according to a study published Thursday in the journal Science. They do this by monitoring the speakers’ gaze, picking up communicative cues and extracting key words from sentences.
Researchers at Eötvös Loránd University (ELTE) in Hungary wanted to find out whether dogs that were “gifted” at learning toy names could also learn new words simply by eavesdropping.
These gifted dogs were assessed and identified when their owners, after seeing social media posts or advertisements, contacted the researchers to say they believe their dog knows the names of toys.
For the study, owners of 10 gifted dogs first introduced two new toys and named them, repeatedly saying the toy names while interacting directly with their pet.
These interactions lasted for multiple minute-long sessions across several days.
Researchers found that “eight minutes was enough for the dogs to learn the name of two new toys,” cognitive researcher and animal trainer Shany Dror told CNN. Seven out of the 10 dogs reliably identified and retrieved the new toys when asked to do so by their owners.
Dror led the study over the past few years while completing her PhD at ELTE and then as a postdoctoral researcher at the Clever Dog Lab of the University of Veterinary Medicine in Vienna.
The researchers repeated the experiment in “overheard” conditions with the same owner and dog pairs. Owners included the name of the new toy in sentences and passed the toy among themselves, but they could not look at or communicate with their dogs, and their dogs were not allowed to interact with them or grab the toy.
To stop each dog from trying to reach the toy, the owners sat at a dining table or on the floor while the dog was put behind a child safety gate, or was in a dog cradle or bed.
Seven out of the 10 dogs were again reliably able to identify and retrieve the new toys after overhearing the toy names – six of them were among the same dogs that performed well in the first experiment.
This showed that gifted dogs “can learn novel object labels by overhearing interactions, in a manner functionally similar” to young children, the researchers said.
Depth of understanding
Eager to test whether the dogs were also using social cues to learn new object labels, like infants do, the researchers carried out a third experiment with eight dogs, four of which were among the original 10.
This time, the pet owners said the name of the toy within sentences only after they had placed the toy in a bucket and the toy was out of view.
Again, when tested, the majority of the dogs correctly identified the new toys – and they still remembered the names of the toys two weeks later.
“So, what we conclude from this is that the dogs are able to learn under very different conditions, and they’re doing it very flexibly,” Dror said, adding that “it tells us the depth of how much these dogs are able to understand our human interactions.”
The findings also suggest the complex cognitive and social abilities that help humans learn by overhearing others probably “evolved before language, and that’s why dogs can also do it,” she continued.
During the domestication p