The Kiki and Bouba Effect: Understanding Modern Linguistics Through a Psychological Phenomenon

Sociology and Psychology

Have a look at the picture above. Which would you name “Kiki”? Which would you name “Bouba”? In a series of psychological experiments, participants mostly named the rounded shape “Bouba” and the angular shape “Kiki”, demonstrating how humans tend to link abstract shapes to similar sounds.

But does everyone associate certain physical characteristics with certain sounds? A theory for the creation of language is that people generally link sounds with different concepts - this later came to evolve into complex speech. However, this begs the question: were these sounds chosen randomly or were they consistently applied to certain symbols and concepts? The psychological phenomenon known as the Bouba-Kiki Effect can help us understand the origins of early linguistics. When we look at an object with a pointy or curvy shape, we tend to use nonsense words to name them. In these psychological experiments, people named the curvy & bubbly shape Bouba and the pointy shape Kiki even though these were nonsense words and the participants were not told what they meant. This was the common result across multiple tests, which were conducted under different languages with non-English speakers.

Cross Modal Correspondence, also known as Sound Symbolism, explains the correlations we make between phonemes (sounds we make) and traits (shape, texture, brightness, size, taste etc.) For example, Sound Symbolism can be observed in the Chinese characters Yuan 圓 (meaning round) and Jian 尖 (meaning sharp). Moreover, visual shapes (rounded or angular) seem to be associated with lip movements. Our lips pucker and curl in when saying “Yuan”, and we widen our mouths to say “Jian”. This could be explained by the sensory-motor connections that exist between cortical visual areas and motor areas.

A potential reason for such a phenomena would be Synaesthesia. This is a neurological condition whereby stimulus is perceived by one or more of the senses simultaneously. This experience is involuntary and automatic, and is different for each synaesthete. This is a common cross neurotransmission between the way we group visuals and sounds. Another possible reason could be repeated association. For instance, larger animals tend to make deeper sounds than smaller animals. Breaking something thin and brittle would likely produce a sharp sound like Kiki, while breaking something round and curved would likely produce a deeper sound like Bouba.

Nonetheless, the Bouba-Kiki Effect does not apply in all circumstances. For instance, the results of a Bouba-Kiki style test on several Songe speakers in Papua New Guinea showed no correlation between phonemes and traits. When looking at the data, there were no observable trends, and the Songe speakers appeared to be picking randomly with no preference. However, it could be argued that the chosen nonsense words, Bouba and Kiki, does not exist in their language, and so it would not make sense for the participants to have linguistic biases. Unfortunately, there is not much research published on negative results. Additionally, it is very difficult and expensive to give linguistic tests to people who have never been exposed to some of the major languages of the world. Nevertheless, the Bouba-Kiki effect is evident in most people. Understanding this phenomenon will help us have a better understanding of how languages are developed and how we communicate, especially through cross language barriers.