Scientists reveal dogs are able to link sounds with shapes just like humans

One shape is soft and rounded, the other jagged and angular.

When asked to match the words to the shapes, the overwhelming majority of people pair "bouba" with the blobby figure and "kiki" with the pointed one.

This tendency holds true across a remarkable range of linguistic and cultural backgrounds, from Hungarian and Japanese speakers to the Himba community in Namibia.

Pre-verbal infants appear to draw the same connections, suggesting the phenomenon is deeply rooted rather than learned.

Researchers at the University of Parma have now demonstrated dogs exhibit this very same instinct.

Their findings were published in the journal Proceedings of the Royal Society B.

The Italian team recruited 70 adult dogs for the experiment.

Each animal was positioned before two screens, one showing a curved shape and the other a spiky one, whilst a recording played one of the two nonsense words on repeat.

The scientists tracked how long each dog gazed at each display.

To prevent any inadvertent human interference, the dogs' owners were required to wear headphones blasting rock music throughout the trial, ensuring they remained unaware of which word was being broadcast.

The results were striking.

Dogs that heard "bouba" devoted more of their attention to the rounded image, whilst those played "kiki" focused on the angular one.

"A spontaneous soundshape association akin to that of humans is also present in adult domestic dogs," the researchers concluded.

The implications extend well beyond canine cognition.

"In humans, soundshape associations are thought to provide a foundation for language emergence and vocabulary formation," the team wrote.

Human language may appear to consist of entirely arbitrary sounds assigned to meanings, yet the bouba-kiki phenomenon hints that certain associations arise naturally — and this latest work suggests they may transcend the boundary between species.

The Parma researchers offered a possible mechanism for this shared trait.

Objects with smooth, rounded forms tend to generate deeper, more fluid sounds when they move or strike one another, whereas sharp-edged items produce harsher, more abrupt noises.

Both human and canine brains may have developed to connect auditory qualities with visual characteristics.

This study adds to a growing body of evidence dogs comprehend far more of human communication than many might assume.

Earlier this year, researchers at Eotvos Lorand University in Hungary discovered certain exceptionally talented dogs could pick up the names of unfamiliar toys merely by listening in on their owners' conversations, mirroring a skill typically seen in toddlers of around 18 months.

That particular ability seems to be uncommon among dogs.

Nevertheless, separate research has shown canine brains handle spoken language in a manner remarkably similar to our own, distinguishing them from other animal species.