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Synesthesia

Do Sounds Have Shapes?

Synesthesia and the bouba-kiki effect

In the ancient kingdom of Babbalot, people worshipped two gods, Bouba and Kiki, whose complementary forces maintained balance in the universe. Bouba and Kiki each had its own symbol, as shown in the diagram below. Although the Babbalot civilization died out thousands of years ago, the spirits of Bouba and Kiki live on, and you may still be able to intuit which symbol stood for each god. Before you read any further, see if you can tell which is Bouba and which is Kiki.

Andrew Dunn / via Wikimedia Commons
Can you tell which is bouba and which is kiki?
Source: Andrew Dunn / via Wikimedia Commons

If you’re like 95% of the people tested, you named the rounded object Bouba and the pointed object Kiki. This example is an illustration of sound symbolism—that is, the idea that certain sounds have certain primal meanings. The bouba-kiki effect was discovered by German psychologist Wolfgang Köhler almost a century ago, and it has been tested in many languages, always with the same result.

Sound symbolism may be but one example of a more general psychological process known as synesthesia, which involves a crossing of the senses. Some people with synesthesia perceive letters and numbers printed in black ink as if they were different colors. Others may perceive tastes as shapes. To a certain extent, we all experience synesthesia, and this can become embedded in the language and culture, as for example when we talk about a “sharp” cheddar cheese.

Noted neuroscientist V.S. Ramachandran proposes that some degree of synesthesia is a core component of the human experience. Thus, as our pre-human ancestors began shaping their first words, they created sound symbols that in some way resembled the things or events they were referring to. Eons later, sound symbolism based on synesthesia was abandoned as vocabularies became large and unwieldy, leading to the arbitrariness in word forms seen in modern languages.

Mysid / Public Domain / Wikimedia Commons
Some people with synesthesia perceive different letters as different colors, even when they’re all printed in black.
Source: Mysid / Public Domain / Wikimedia Commons

However, there are still language-specific sound patterns that seem to be associated with particular meanings. For instance, many words in English beginning with gl have to do with the perception of light, such as glow, gleam, and glitter. At the same time, there are also plenty of words beginning with gl that aren't related to light, such as gloat, glob, and glide. Systematic sound symbol patterns are found in many languages.

Another example of sound symbolism is onomatopoeia, which is a word that represents a sound, like thud or bang. These sound words vary widely from language to language. For instance, pigs say oink in English but bubu in Japanese. Thus, while these words bear some resemblance to the sounds they symbolize, they’re also shaped by the cultures in which they’re used.

Ben Salter / Wikimedia Commons
This pig makes different sounds depending on the language you speak.
Source: Ben Salter / Wikimedia Commons

It’s not immediately obvious why there isn’t more sound symbolism in language, since it should be an aid in learning and remembering words. You might expect similar concepts, such as DOG and WOLF, to have similar words to label them. In fact, when we encounter new words, we often assign them meanings related to similar-sounding words. We do this, for example, when we read Lewis Carroll’s famous nonsense poem Jabberwocky:

'Twas brillig, and the slithy toves
Did gyre and gimble in the wabe….

No doubt some sort of image comes to mind as you read these lines.

Generally speaking, though, the sound of a word gives us no information about its meaning. This principle is known as “the arbitrariness of the symbol,” and some psychologists think it’s necessary given the way our memory works. Familiar sounding words are easier to learn than unfamiliar words. But if two words with similar meanings also had similar pronunciations, we’d be very likely get confused as we tried to recall them.

By the way, if you’re wondering why the bouba-kiki effect is found universally, here’s the standard explanation. When you say bouba, you purse your lips, making the shape of your mouth round. But when you say kiki, you spread your lips, making the sides of your mouth pointed. Show your friends and family members the bouba-kiki picture and see if they can tell which is which.

References

Monaghan, P., Christiansen, M. H., & Fitneva, S. A. (2011). The arbitrariness of the sign: Learning advantages from the structure of the vocabulary. Journal of Experimental Psychology: General, 140, 325–347.

Monaghan, P., Mattock, K., & Walker, P. (2012). The role of sound symbolism in language learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 38, 1152–1164.

Ramachandran, V. S. & Hubbard, E. M. (2001). Synaesthesia: A window into perception, thought and language. Journal of Consciousness Studies, 8, 3-34.

David Ludden is the author of The Psychology of Language: An Integrated Approach (SAGE Publications).

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