Dogs Seem to Agree with Humans That 'Bouba' Is Round and 'Kiki' Is Spiky

Researchers tested whether dogs, like humans, match rounded-sounding nonsense words to round shapes and sharp-sounding words to spiky shapes using a two-condition experiment with 70 pet dogs. In the main test 51 dog-owner pairs entered a room with two screens and speakers; shapes swapped left/right while "Bouba" or "Kiki" were played and dogs were filmed by a GoPro. An AI tracked head orientation as a proxy for gaze. A second replication with 19 dogs had owners wearing headphones playing music so they could not hear the stimuli, removing possible unintentional human cues.

Dogs looked more at the rounded shape when "Bouba" was played and more at the spiky shape when "Kiki" was played, indicating a cross-modal sound-shape association similar to humans. A general bias toward spiky shapes appeared in the first experiment but vanished when owners were deafened to the sounds, leading authors to consider owner cueing or species-specific facial morphology as explanations. The work, published in Proceedings of the Royal Society B, provides preliminary evidence of shared audio-visual mapping across species and raises questions about how dogs attune to human language and visual signals, while acknowledging further research is needed.