By: Joshua Watson
Edited by: Gelsey Brizo
Sound Symbolism in Language Development
Suppose you’re presented with two abstract shapes like those pictured above: one with sharp, jagged edges, and another with smooth, rounded curves. Given no further information, you’re asked to identify one of the shapes as “bouba,” and the other as “kiki.” How would you respond?
If you identified the jagged shape as “kiki,” and the rounded shape as “bouba,” then you agree with almost everyone who has been asked this same question since it was first developed by psychologist Wolfgang Köhler in 1929. This bouba/kiki effect, as it is referred to, suggests that the way we attach sounds to shapes or images is not entirely arbitrary.
The generally accepted explanation for the effect is that humans have a tendency to match vocal sounds with visual shapes that have a similar contour. While “kiki” has a sharp inflection and requires sharp movements of the tongue to speak, “bouba” has a smooth, rounded inflection which requires a rounding of the mouth to speak. Therefore, we are more likely to refer to the jagged shape as “kiki,” and the rounded shape as “bouba.”
This effect has been demonstrated in multiple populations regardless of their native language, and can be modified to use different shapes and sounds which adhere to the same basic principle. In addition, the bouba/kiki effect is thought to form the basis for a concept called sound symbolism, which posits that vocal sounds have inherent meaning to us. Sound symbolism also has implications for understanding the evolution of language and the creation of metaphors, as well as the development of language in infants.
In fact, research suggests that the effect is present even in preverbal infants younger than 12 months old. A recent study conducted at the Tamagawa University in Japan tested the bouba/kiki effect in a group of 11-month-old infants by presenting them with abstract shapes, similar to those above, paired with recordings of the words “kipi” and “moma.” The experimenters then measured the brain activity of the infants using Electroencephalogram (EEG) recordings when the shapes and words were either matched or mismatched based on their expected sound symbolism.
Results of the study suggest that infants may be recruiting the same brain networks that adults do in processing word meaning. When the sound-shape pairs presented were symbolically matched, the infants showed strong coherence of activity in brain areas involved with cross-modal language processing, or language processing, which involves multiple types of perception. When the sound-shape pairs were mismatched, the infants showed brain activity similar to that seen in adults when they are exposed to sentences that have unexpected or nonsensical endings that are difficult to process. Taken together, this suggests that infants are employing a very basic mapping of sounds with visual objects, using language pathways to provide an early scaffolding upon which semantic, or meaningful, language learning can later build.
The Tamagawa University study is the first to demonstrate a neurological basis for sound symbolism in infants. However, previous behavioral studies have suggested that infants as young as 6 months old can associate words with the objects they refer to, at least at a very basic level. A 2012 study presented infants in the 6-9 month age range with sets of images, like food items, and guided them toward a target object using sentences spoken by their parents, such as “Look at the apple.” Surprisingly, results showed that the infants were able to fix their gaze on the target even when it involved an object with no definite shape, such as milk or juice. While this study does suggest that infants are attempting, with some success, to associate words with meanings at a very early age, their performance in experiments such as these is significantly less advanced before 14 months of age.
The bouba/kiki effect demonstrates a simple principle of sound symbolism which can be used by infants to make direct associations between sounds and objects, but it’s easy to see how this method will quickly lose its effectiveness. Eventually, someone is going to ask “Where is the apple?” and the correct answer will be “Well, it’s not here,” which requires a more abstract concept of objects that can’t be immediately perceived. Regardless, language acquisition is an ongoing process, and part of that process involves discovering the limitations of one method and finding a new method to help you build up your cognition as you continue to learn.
Research aimed at understanding exactly how we acquire more meaningful concepts of words and phrases is ongoing, and competing theories abound. However, it is clear that language learning starts at a very early age. By identifying the building blocks upon which language is acquired and reinforced, we can support the learning process through science-based instruction that is tailored to the developmental stage of every learner.