Dogs are susceptible to the bouba-kiki effect

Recent studies have demonstrated that humans, regardless of their cultural background, consistently link smooth or rounded shapes with the word "bouba," and jagged or spiky shapes with the word "kiki." This phenomenon, known as the bouba-kiki effect, has even been observed in chicks and possibly macaques. To determine if dogs share this same inclination, Eleonora Biffi and her team from the University of Parma, Italy, conducted a series of experiments involving 51 owners and their adult dogs.

During the first experiment, the researchers presented a rounded shape and a spiky shape to the dogs, accompanied by the words "bouba" and "kiki" respectively. Astonishingly, 56% of the dogs leaned towards the round shape when hearing "bouba," while 63% focused on the spiky shape when hearing "kiki." To rule out the possibility that the dogs were influenced by their owners' reactions, the same experiment was repeated with the owners wearing headphones to block out the auditory stimuli.

The results remained consistent, with a slight inclination towards round shapes for the word "bouba."

The researchers believe that if animals without human-like language can exhibit this sound-symbolism association, it suggests that certain mechanisms underlying this phenomenon may not be exclusive to language. Instead, they could be rooted in more general principles of how the brain integrates information from various senses.

While the effect might be influenced by dogs' familiarity with human speech or their long history of co-evolution with humans, further investigations are underway to explore these possibilities. Biffi and her team are currently gathering data on puppies and wild canids, such as foxes, and are also interested in investigating whether cats exhibit the bouba-kiki effect. The study's findings have been published in Proceedings of the Royal Society.