Try this before reading on. Picture two shapes, one a soft, rounded blob and the other a jagged star with sharp points. One is named Bouba, and the other is named Kiki. Which is which?

If you called the blob Bouba and the star Kiki, you are in good company. A new study suggests dogs may lean the same way. Researchers at the University of Parma in Italy found that dogs looked longer at the rounded shape when they heard Bouba and at the spiky shape when they heard Kiki, in a study published in Proceedings of the Royal Society B.

For the millions of American households with dogs, the finding offers a small window into how pets may process the sounds of human speech. It also hints that one of the most famous effects in language research may have roots older than language itself.

A Century-Old Test of Sound and Shape

The bouba-kiki effect dates back to experiments in the 1920s. It suggests people connect certain speech sounds with certain visual shapes, so that soft, rounded sounds feel round and sharp, clipped sounds feel spiky.

The pattern holds across very different languages. A 2022 study of 917 speakers of 25 languages, spanning nine language families and ten writing systems, found that a majority matched bouba to the rounded shape and kiki to the spiky one. That consistency is why researchers have long suspected the link reflects something basic about how brains connect sight and sound.

If the effect is truly that basic, it might not be limited to humans, which made dogs an appealing subject. Dogs have lived alongside people for thousands of years and pay close attention to human voices.

Seventy Dogs, Two Screens and a Speaker

The team, led by animal behaviorist Eleonora Biffi, tested 70 pet dogs in two experiments, according to ScienceAlert. Each dog sat in a room facing a screen and speaker on the left and another on the right, with a rounded shape on one screen and a spiky shape on the other.

Over about 15 minutes, the speakers played the words Bouba or Kiki while the shapes swapped sides. A GoPro camera recorded each dog, and an AI tool tracked the direction of its head as a stand-in for where it was looking.

Swapping the shapes from side to side mattered. Many dogs simply prefer looking left or right, so moving the shapes kept a side preference from masquerading as a word preference. The researchers then checked whether the dogs' looking patterns differed from what chance alone would produce.

Across the study, dogs looked significantly more at the rounded shape while Bouba was played and at the spiky shape while Kiki was played. In the researchers' words, "dogs looked significantly more at the rounded shape while 'Bouba' was played."

Ruling Out the Owner Effect

Dog owners know their pets read human body language closely, which raised an obvious concern. In the first experiment, 51 dogs sat with their owners, who could hear the words. Those dogs also showed an overall tendency to look at the spiky shapes.

To check whether owners were unconsciously steering their dogs, the team ran a second experiment with 19 different dogs whose owners wore headphones playing rock music, so they could not hear the words. The general bias toward spiky shapes disappeared, but the sound-shape matching held.

The headphone design is a common safeguard in dog cognition research. Dogs are skilled at picking up tiny human cues, such as a glance or a shift in posture, and the music meant owners had no idea which word was playing at any moment. If owners had been steering their dogs, the sound-shape matching should have weakened in the second group, and it did not.

The authors consider owner influence an unlikely explanation for the spiky bias anyway, since people usually prefer rounded shapes. They suggest another possibility — dogs' own faces, especially those of wolves and ancient dog breeds, are more angular than the round faces of human babies, which could give them a different visual preference.

Limits of a Looking-Time Study

This is an experimental behavior study with a modest sample. It shows a pattern in where dogs looked, not that dogs understand the words or think of shapes the way people do. Looking time is an indirect measure, and head direction tracked by software is an approximation of gaze. The researchers say more work is needed before concluding that dogs reliably link Bouba with round shapes and Kiki with sharp ones.

The study also did not report results by breed, age, or training history, so it cannot say whether some dogs show the effect more strongly than others. Those would be natural questions for follow-up research.

For owners, the practical takeaway is light but real. Dogs appear to be tuned in not just to familiar words and tone of voice but possibly to the sound qualities of speech itself, which may help explain why short, sharp commands and soft, drawn-out praise can land so differently. That is an inference, not a finding of this study, but it fits a growing body of research on how closely dogs follow human communication.

The bottom line is that dogs may share one of humanity's most widespread sound-and-shape intuitions, which would suggest the link evolved before spoken language — though that idea still needs testing. Owners curious to try a version at home should keep it playful and remember that a single dog's glances prove nothing on their own.

What Readers Want to Know

What is the bouba-kiki effect?

It is the widespread tendency to match the made-up word bouba with a rounded shape and kiki with a spiky one. A 2022 study found the pattern held across 25 languages and ten writing systems.

What did the dog study find?

Dogs looked significantly more at a rounded shape when they heard Bouba and at a spiky shape when they heard Kiki, suggesting they may make a similar sound-shape link.

How many dogs were tested?

Seventy pet dogs took part across two experiments, 51 in the first and 19 in the second.

Could owners have influenced the results?

The researchers tested this by having owners in the second experiment wear headphones playing music. The sound-shape matching still appeared.

Does this mean dogs understand words?

No. The study measured where dogs looked, not whether they understood meaning. The authors say more research is needed.

Who ran the study?

A team led by animal behaviorist Eleonora Biffi at the University of Parma in Italy published in Proceedings of the Royal Society B.