Tag Archives: shape

Sandpaper is to Ruki as Satin is to Lula

In class we discussed the phenomenon that is the bouba/kiki effect. This study was developed in 1929 by Kohler but has been repeated with different variations since then. Try it yourself here: which of these shapes is bouba and which is kiki?

Which is bouba and which is kiki?

You probably said the sharp angular shape was kiki and the bubbly curvy shape was bouba, right? You’re not alone, when this study was repeated by Ramachandran and Hubbard in 2001, 95% of people picked the left shape as kiki and the right shape was bouba (Ramachandran and Hubbard, 2001). This experiment contributed to the ongoing science of understanding synesthesia. Synesthesia is a condition where a person experiences sensations in one modality when another modality is stimulated (Ramachandran and Hubbard, 2001).

How someone with grapheme-color synesthesia might perceive the alphabet and numbers

A modality is a way of experiencing something; for example if a person with synesthesia heard the note C, he/she may associate that note with the color red. There are many types of synesthesia, the most common being grapheme-color synesthesia during which a person correlates a letter or number with a specific color.

Since the original bouba/kiki experiment, many studies testing a variety of associations between different modalities have been published. In one paper, the authors Etzi et al. study the association between nonsensical words and physical touch. Twenty five subjects in their early 20’s, who were blind folded and wore ear plugs, were asked to describe and rate the experience of having different textures rubbed on their arms. Samples of different textures included cotton, satin, tinfoil, sandpaper, and abrasive sponge. The hairy part of the skin was targeted since there is evidence that a certain type of fiber only found in hairy skin is associated with feelings of pleasantness (Loken et al., 2009). Participants were then asked to rate the tactile simulation with a variety of nonsensical words, adjectives, and emotional descriptions. Scales of nonsensical words such as kiki vs bouba, ruki vs lula, and adjectives such as loud-quiet, beautiful-ugly, feminine-masculine were used. When describing emotion, participants were presented with an emotion and asked to rate whether the texture represented this emotion “not at all” or “very much”. Analysis of results show that rougher materials such as sandpaper and abrasive sponge were rated as more “kiki”, “ruki”, and “takete” while smoother materials such as satin were rated as more “bouba”, “lula” and “maluma” (Etzi et al., 2016). This may be explained by the fact that phonemes /t/, /k/, /p/, are “strident and plosive” consonants while /l/, /m/, /n/ are sonorant and continuant consonants (Nielsen and Rendall, 2013). Another interesting result was that smoother textures like satin and cotton were described more as “feminine” and “beautiful” while rougher textures like sandpaper were described as “masculine” and “ugly” (talk about gender norms am I right?) (Etzi et al., 2016). Overall, this study concluded that there is an association between nonsensical words and perceptions of tactile textures.

While this study provides more evidence into cross modality correspondences, there is a weakness. Hairy skin was targeted for stimulation since there would be greater fiber response; however, people have different amounts of body hair which may affect the tactile stimulation experience between participants, skewing the results. There are still many different cross modal associations that have yet to be studied that would be interesting future experiments. By understanding the different associations, we are able to better understand just how interconnected the brain is.

The significance of cross modal associations is more ubiquitous than you might think. When we go to the store to pick up groceries and maybe a bottle of wine, activation of our different senses gives us subconscious reactions to these different stimuli. The shape of that one wine bottle may be associated with harsh, rough, loud words while the shape of another may be associated with soft, flowy, harmonious words. The words that we associate with that shape will influence which bottle we decide to buy.

Different wine bottle shapes

The decisions we make when shopping are based on product design and how we perceive an object from our different senses. So next time you’re shopping for wine, instead of going for the cheapest option, examine the shape, the texture, and feel of the bottles. Introspect and ask yourself, how does the design really make you feel?


Etzi, R., Spence, C., Zampini, M., & Gallace, A. (2016). When sandpaper is ‘Kiki’ and satin is ‘Bouba’: An exploration of the associations between words, emotional states, and tactile attributes of everyday materials. Multisensory Research, 29(1-3), 133-155.

Hanson-Vaux, G., Crisinel, A.-S., & Spence, C. (2013). Smelling shapes: Crossmodal correspondences between odors and shapes. Chemical Senses, 38(2), 161-166.

Löken, L. S., Wessberg, J., McGlone, F., & Olausson, H. (2009). Coding of pleasant touch by 477 unmyelinated afferents in humans. Nature Neuroscience,12, 547-548.

Nielsen, A. K. and Rendall, D. (2013). Parsing the role of consonants versus vowels in the 510 classic Takete–Maluma phenomenon, Can. J. Exp. Psychol. 67, 153–163.

Ramachandran, V. S., & Hubbard, E. M. (2001). Synaesthesia- A window into perception, thought and language. Journal of Consciousness Studies, 8(12), 3-34.

Picture 1: https://en.wikipedia.org/wiki/Bouba/kiki_effect

Picture 2: http://synesthesia-test.com/synesthesia-test

Picture 3: https://chwine.com/tasting-room/decoded-intro-to-wine-bottle-shapes/