The Bouba-Kiki Effect – A Test for Synesthesia?

bouba kiki effectHey there, folks! How’s it going? Good? Good. Let’s begin by addressing the question posed in the title of this post. If you’re not familiar with The Bouba-Kiki Effect, bear with me. We’ll start with a basic explanation and move forward with some of the deeper implications. If you’ve ever searched for ‘synesthesia test’, ‘test for synesthesia’, or something similar, chances are that you’ve come across the Bouba-Kiki image (shown lower in this post): two distinct shapes – one Bouba, and one Kiki. Which is which, though? (Scroll down, look at the image, and decide for yourself.) Actually, there’s no correct answer. This image (coupled with the question of which is Kiki, and which is Bouba) is not so much a test for synesthesia as it is evidence of the fact that shapes are not necessarily named arbitrarily – an experiment first conducted in 1929 by psychologist Wolfgang Kohler (pictured above-left). Don’t leave yet, would-be synesthetes – his findings (and those of others who’ve done similar experiments since) are quite interesting.

The experiment, first conducted by Kohler on the island of Tenerife (whose occupants primarily speak Spanish), consisted of the psychologist showing subjects a picture of two figures (very similar to those shown below) and asking them which was named “takete” and which was named “baluba”. Interestingly enough, the results were overwhelmingly similar – the data revealing that the majority of test subjects assigned the name “takete” to the jagged, star-like shape (on the left) and “baluba” to the blobbish, rounded shape (on the right).

synesthesia mapping

Over a half a century later, in 2001, a nearly identical experiment was conducted by Vilayanur Ramachandran and Edward Hubbard – using the names “kiki” and “bouba” rather than “takete” and “baluba”. In using American college students and Tamil speakers in India as subjects, the two found that 95-98% assigned the name “bouba” to the rounded shape and “kiki” to the jagged. Pretty cool, huh? So, what are the implications? What does this have to do with having synesthesia?

Synesthesia-Like Mappings

Born from the original experiment (by Kohler) and those subsequent is the “Bouba-Kiki Effect” – a strong suggestion that the naming of objects (whatever those objects may be) is not entirely arbitrary. Instead, names may be derived from the way formations of specific sounds relate to the physical attributes of objects. This may sound confusing, and it probably is, but it’s also somewhat intuitive. For instance, in the case of our experiment, subjects may have been more inclined to assign the name “bouba” to the rounded shape because, when spoken, the pronunciation of that name requires a more rounded mouth. Similarly, the K sound in “kiki” is harder – more jagged, if you will. We’re just scratching the surface, obviously.

The connections drawn between the neurological condition of synesthesia and the Bouba-Kiki Effect are fairly obvious. In fact, the effect has been described as being representative of “synesthesia-like mappings” in the brain, where one sense has a steadfast, underlying connection to another. We’ve discussed personification previously, and for me, this concept of sound symbolism is just another gateway through which personalities can be assigned to and perceived from inanimate objects. Interesting – to say the least.

Test or Not a Test?

All things considered, I’d say that the Bouba-Kiki image (and question) is less of a synesthesia test, and more of an insightful look into the condition itself. For me, it’s affirmation that we all have a little synesthete in us. What do you think?

35 Comments on “The Bouba-Kiki Effect – A Test for Synesthesia?”

  • I wonder how much of it has to do with the shape of the letters in the words, as much or even more than the sound or mouth shape of the words? Ks and I’s are sharp and Bs and Os and As and U’s are round.

    • by Travis

    Hey Amy,

    Great point! I might’ve glossed over it in my research for the post, but it’s quite possible that others have had a similar contention with regards to the letter shapes. Perhaps it’s the amalgamation of these word/letter traits that defines Bouba and Kiki in our minds.

    Thanks for the comment!

    • by Eoin

    Hey I chose the bouba for the jagged shape instead of what the other majority had chosen, can someone please tell me what this might mean??

    • by Travis

    Hey Eoin,

    Thanks for stopping by. Although most people choose the jagged shape as Kiki, there will always be those (like you) that reverse the two. This isn’t necessarily indicative of anything specific; perhaps it just means that you think a bit differently than the average Joe!

    • by Cheyenne

    Hi Everyone,

    I’m a high school student attempting this experiment on my own is there any pointers I could get before I get started?

    • by Travis

    Hey Cheyenne,

    One thing I’d suggest doing is making sure that your sample is large enough. Testing 100 of your classmates, for instance, will give your results more statistical significance than if you were to test only 10. Good luck!

    • by Audrey

    I agree with you final thought. I think synesthetic phenomena form a large spectrum that most people experience on various degrees, so probably that’s part of it. Human mind functions a lot on association, i’m not sure where to draw a line between what’s synesthesia and what’s not!

    • by Travis

    Hey again, Audrey,

    I think you hit the nail on the head. It’s difficult to draw a line between what experiences are synesthetic and what are simply associative in nature. As a non-synesthete, I think about this every time that I encounter something that “smells like something else tastes.” It’s always been a weird phenomenon to describe, but I’ve asked plenty of others about it, and they willfully admit to having similar experiences.

    Thanks again for the comment!

    • by Cheyenne

    This is going to be difficult seeing as how there are only 35 students in my high school, but I will proceed to test them all. Thank you!

    • by Cheyenne

    Just wanted to say thank you for the advice, it really helped a lot in the long run. When I turned the experiment into my online Psychology class I got 100%. I do believe interviewing more students really did help. So thank you so much!

    • by Travis


    Awesome! Congrats on the hundo! What were the results like? Any interesting insights?

    • by Cheyenne

    Most of the people I interviewed chose the jagged star as Kiki and the blob and Bouba, but I started seeing a pattern so I switched up the order of the shapes and the names that i gave them and it seemed to have an effect in what they named each shape. It was interesting enough for me to write in my analysis. Once again thank you so much for your help.

    • by Kimberly

    I thought this was a very interesting experiment. I am in high school and I’m doing this experiment online. I think it’s interesting that most people chose the same answer. It’s weird how we associate how a word sounds with a cetain shape. I wonder what people would have chosen if it was both jagged and blob-like. This experiment makes you think.

    • by Cheyenne

    I totally agree with you on that note, I have just recently finished the experiment myself. It really made me change my point of view on how students and adults alike the jagged shape with a sharper word and the blob with a softer rounder word.

    • by Lene

    Hi! (this might not be the right place for my post, but I’ll take the chanche..)

    Recently, I have had this vision/idea that I can’t seem to let go of. I live close to a beautiful park, and I love to go for a walk there now and then. One day, I went there when it was raining. The sun was shining too though. I sat down on the grass, closed my eyes, and suddently I had this feeling of being surrounded by scaffoldings. (I know!) I also felt a line above the horizon, filled with yellow. This “vision” appears only in this certain kind of weather. There were other small things that appeared in my imagination too, there seemed to appear a new thing, (for example a hammer), for every little new sound I pay’ed attention to. Is this synesthesia? Or am I just forcing my imagination to “feel” things? Either way, this park is even much more exiting and beautiful to me, after this experience! 🙂 I know that I have synesthesia when it comes to numbers, weekdays, letters and personalities, but I’d like to know what sort of synesthesia this “vision” is? If it is at all?

    • by Travis

    Hey Lene,

    Thanks for sharing! This is pretty interesting. While I’ve never come across anything quite like this before, I would guess that it’s some function of your synesthetic mind. Just curious: Does snow (presuming you get snow wherever you live) trigger these experiences?

    • by Alex

    Hi Travis.

    I’m a University student in Scotland doing a study on how people with sound based Synaesthesia and those without any understand radio output.
    I was thinking the same thing about association. And because of early learning could one be taught through aural mean to associate things and understand this medium better?
    I am going to attempt a focus group with some Synaesthetes and some non-syneasthete to see where the line could be(with adults). And if it can be taught, what cold this mean for radio broadcasting.
    if interesting I’ll type up my findings.

    • by Travis

    Hey Alex – sounds pretty interesting. You pose a good question. Once you’ve conducted your study, you’re welcome to post your findings here (no matter the results). We’re happy to house these kinds of investigations into synesthesia!

    If you publish your findings somewhere else, feel free to send us the link. We’ll be sure to tweet it out! 🙂

  • I also chose the opposite than most and so did my daughter who is my mini me. My husband chose with the majority and so did our older daughter who is the female version of him. My mini me and myself chose the blob as Kiki because it sounds nice and sweeter and the the blob looks nice and sweeter and Bouba as the jagged one because the name bouba sounds more rough and mean to us. So, we are weird aren’t we? Total nut burgers! I asked them separate too! So funny!

    • by Travis

    Hi Laura,

    Interesting! Well, some have to make up the minority. 😉

    • by arkadianriver

    Something similar to kiki/bouba interested me about 13 years ago, after reading some Sumerian myth. (And also considering what “Om” means in eastern meditation.) In Sumer, the two great deities are single syllables (An and Ki), and later generations of deities/humans combine these and other simple sounds (Enki, Enlil, Enkidu). I always wondered if there was intended meaning in that. For example, “An” is the god of the expanse of the universe, and your mouth expands to say it (“Aaaaan”). “Ki” is the goddess of the earth, which is “in” the universe, thus a sharp tightened sound. Then “lu” for man (tightened lips) and “sal” for woman (open mouth) make sense when you think of a phallus compared to a womb and the sounds that could represent each. Perhaps creation is nothing more than “bouba” blobs being divided or sliced by “kiki” edges and morphing into other lu, sa, lil, in, and other simple sounds that represent different characteristics that Sumerians experienced in daily life. Wild hypothesis.. who knows.. I didn’t live back then and create the language, nor am I a linguist or anthropologist. And, it doesn’t quite line up anyway, if you look at the representations of these in writing: (unless you think of the representation of ki to be what your mouth looks like when you say it with all your teeth showing.) 😉 The written representation is still sharp and pointy for sal. So.. after An and Ki, Enki being the combination of them, and An-nunna-ki being their offspring, the logic of other names doesn’t follow so clearly without understanding with more research. Nevertheless, it’s interesting to consider, in light of Dr. Ramachandran’s assertions about the logic of rounder shapes corresponding to rounder sounds and sharper shapes to sharper sounds. I think we’d need to study the shapes and symbols across civilizations to see if they also correspond to similar sounds.. otherwise, I’m inclined to agree with Amy in the very first comment.. that B (the rounded letter we learned in school) looks like a the Bouba Blob, and K (The sharp-edged letter we learned in school) looks like the Kiki Krumble.. which doesn’t prove anything except that we recognize the alphabet we learned, rather than something we’re internally wired for. I’d like to think there’s some neurological commonality among us with respect to language, but I think the kiki/bouba phenomenon doesn’t prove it very well, given our recognizable alphabet. If all alphabets/symbols follow a similar pattern with respect to their language throughout time, then that would make it more interesting. But, in this simple case, it’s highly likely that the bouba “egg” came after the B “chicken” rather than the other way around.

    • by arkadianriver

    Let me retract some of what I said. 😉 I just read this in another blog about the effect (, which states:

    “There was some argument that the written word was an influence, at least on English speakers. The letter ‘k’ and the lower case ‘i’ were straight and sharp letters, while every letter in ‘bouba’ is rounded. This might cause people to match the shape of the letter with the shape of the object. Recently, though, it was shown that The Bouba-Kiki Effect was in full force for children as young as two and half, far too young to read. It’s the sound of the words that makes people associate them with one shape or another.”

    I’d like to see the full data, but this is indeed promising. Neurology is fun! 🙂

    • by arkadianriver

    These comments have been brought to you by the letter “2,” which is always blue and tastes like glue. 😀

    • by Julianna

    Hi, my name is Julianna and I am doing SCIENCE PROJECT on THE BOUBA KIKI EFFECT . I would like to know which one is Bouba and Kiki?

    • by Travis

    Hi Julianna,

    Which do you think is which? 😉 Most dub the rounded shape Bouba and the more jagged shape Kiki. Hope this helps!

    • by Donna

    I tried this experiment on someone without writing the names (speaking them only) and mixing up the shapes so that “bouba” came first, and I asked, “Who is Kiki and who is Bouba?” The response was the expected one.

    • by Annah

    Well when I did this test, I chose Kiki as the jagged one and Bouba as the more rounded one and I noticed that when I did it was because of the personalities of the names and the shapes. Kiki is more of a happy, outgoing kind of name while and jagged one is unique like Kiki. Bouba is more like an introvert, but not on the happy side, while the shape was a little bit happy, but quiet like the name. The personalities between the two are similar and that’s probably why I chose what I did. 🙂

    • by Kristina

    I believe, that this test of KIKI and BOUBA shows that there is a synesthete in almost every of us, and what I really like is that in this way you can explain those people what you feel at least a little bit, because every synesthete once thought that he / she is the only crazy- in- this- way- person and now it is explained and shown to people.

    • by Winter xP

    Hello! I’m Winter.. and I’m doing this project in high school, because I’m taking Psychology… and I don’t have many people to test on.. only my immediate family right now. How can I make sure my results will be correct? Or accurate? Help mee? Thanks ): <3

    • by Danny

    Just discovered this concept researching for a course on why we collecd art. And from some othe recent readings, I wonder if the typical answers given have anything to do with (if they are proeven to exist) epigentic rules that are instilled in our brains along with gene-cultue co-evoultion is so many of us picking those names, of which I did. Any thoughts?

    • by Alyssa

    Very good info 🙂

  • […] some level, however, we all may be a little bit synesthetic. Some evidence for this comes from the Bouba-Kiki Test, invented by Estonian psychologist Wolfgang Kohler in 1929. Test subjects are shown pictures of two […]

    • by paigequizzy

    Hey guys, I saw the kiki- bouba effect on sciencebuddies, and I’ve decided to try the experiment for my science fair project. I’m only supposed to change one variable, to make it a “fair” test. I was just wondering if I’m changing too many variables by changing the colors of the shapes. I made some kikis with boubas inside, and some boubas with kikis inside, and I didn’t know if that was too much… I’m already changing a variable when I change the test subject, and changing from kikis to boubas to kikis to boubas to boubas…

    • by Marko

    For those speculating that it has something to do with letters and the shapes of letters.

    This has been tested on people without written language and on children, they all have broadly the same responses as most people.

    It doesn’t just work with shapes either, fizzy water and still water, Milk chocolate and Dark Chocolate, all can be Kiki or Bouba.


    • by Sheree

    I hope I can get a response, I realise this is an old page now but I cannot find an answer.

    When I did the test there were also two colours mixed. I arranged by colour not shape. Is there any answer for this or am I an anomaly. Or was my test simply flawed? Thank you.

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