The seemingly simple question of whether the sound “bouba” feels round, and “kiki” feels spiky, has captivated researchers for decades. Now, a new study reveals this association isn’t limited to humans – newly hatched chickens exhibit the same preference, challenging previous assumptions about the origins of this curious phenomenon.
The “bouba/kiki effect,” first observed in , demonstrates a consistent, cross-cultural tendency for people to associate certain sounds with specific shapes. Rounded shapes are overwhelmingly linked to the sound “bouba,” while spiky shapes are linked to “kiki.” The effect has been documented across numerous languages and even in infants as young as old, suggesting an innate, pre-linguistic basis. It’s even gained enough prominence to warrant a detailed entry on Wikipedia.
Early attempts to explain the effect focused on the potential connection to actual words. Researchers hypothesized that the sounds might resemble words commonly associated with those shapes in various languages. However, studies involving speakers of diverse languages and writing systems quickly debunked this theory. The consistency of the effect across linguistic boundaries pointed towards a more fundamental cognitive process.
Intriguingly, previous research had failed to replicate the bouba/kiki effect in other primates. This led some scientists to speculate that it might be a uniquely human ability, potentially linked to the complex cognitive processes underlying language development. If the effect was exclusive to humans, it could have offered insights into the evolutionary origins of our linguistic capabilities.
However, a team of Italian researchers – Maria Loconsole, Silvia Benavides-Varela, and Lucia Regolin – have now cast doubt on that hypothesis. Their recent work, focusing on newly hatched chickens, suggests the bouba/kiki effect extends far beyond the primate family. The researchers chose chicks specifically because of their unique developmental stage. Unlike human infants of a comparable age, chicks are immediately mobile and capable of actively interacting with their environment, allowing for more direct behavioral observation.
The study, detailed in recent reports, involved presenting chicks with visual stimuli – rounded and spiky shapes – while simultaneously playing the sounds “bouba” and “kiki.” The researchers then observed the chicks’ movements, noting whether they oriented themselves towards the shape that corresponded with the sound. The results mirrored those seen in human studies: chicks consistently preferred to approach the rounded shapes when hearing “bouba” and the spiky shapes when hearing “kiki.”
This finding is significant because it suggests the bouba/kiki effect isn’t necessarily tied to higher-level cognitive functions associated with language. Instead, it may be rooted in more basic perceptual mechanisms related to how the brain processes auditory and visual information. The association could stem from a fundamental link between the acoustic properties of the sounds and the visual characteristics of the shapes. For example, the rounded sound of “bouba” might activate neural pathways that also respond to curved lines, while the sharper sound of “kiki” might activate pathways associated with angular forms.
The implications of this research extend beyond simply understanding a curious perceptual phenomenon. It raises questions about the evolutionary origins of sensory integration and the shared cognitive mechanisms that may exist across different species. If the bouba/kiki effect is present in both humans and newly hatched chickens, it suggests that these mechanisms may have evolved much earlier in the animal kingdom than previously thought.
the study adds to a growing body of evidence suggesting that our perception of the world is not solely based on learned associations but is also shaped by innate predispositions. While experience undoubtedly plays a role in refining our perceptual abilities, some fundamental connections between sensory modalities may be hardwired into the brain.
Interestingly, related research published in explored how artificial intelligence can mimic human reasoning processes, even demonstrating the bouba-kiki effect in “naïve baby chicks” through AI modeling. This convergence of research areas – animal cognition, human perception, and artificial intelligence – highlights the potential for cross-disciplinary insights into the fundamental principles of intelligence and sensory processing.
The bouba/kiki effect, once considered a quirky psychological curiosity, is now emerging as a valuable tool for understanding the building blocks of perception and cognition. The discovery that even newly hatched chickens share this preference underscores the universality of this phenomenon and opens up new avenues for exploring the neural basis of sensory integration across the animal kingdom.
