Re:Evidence of the bouba-kiki effect in naïve baby chicks
by selridge on Saturday February 21, 2026 @09:20PM
(#47107461)
>But I guess it's about why so we associate those with spiky shapes
I think the why just got a lot tricker than we imagined. Because we failed to replicate this experiment on other primates, we couldn't avoid a semantic suspicion about those associations. Now we probably have to set semantics aside or let it get a lot weirder, because we can replicate across ~300My.
>surely it's because they represent sharp immediate changes in frequency?
Maybe, and I think "multi-sensory signal processing" is the best framing, but the representation could also carry harder to think about things like "harm".
It's also super cool because the bouba-kiki effect framing was chosen due to methodological convenience for linguists and cultural anthropologists and their experimental bounds, not neuroscientists or signal processing folks. We could potentially find other experiments quickly, since chicks are a model organism and the mechanism is clear.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by canjobear on Saturday February 21, 2026 @10:48PM
(#47107934)
> But I guess it's about why so we associate those with spiky shapes, though surely it's because they represent sharp immediate changes in frequency?
Sure, but it's a very abstract connection between objects being sharp in vision and frequencies changing sharply in hearing. There's no guarantee any given organism would make the connection.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by oasisaimlessly on Sunday February 22, 2026 @12:07AM
(#47108384)
I don't think it's abstract at all. Rub something sharp (anything from a stick to a phonograph needle) on an object and you'll directly transcribe its spatial frequency spectrum into an audio frequency spectrum.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by PaulDavisThe1st on Sunday February 22, 2026 @10:24AM
(#47111734)
"Spatial frequency spectrum" typically refers to visual elements of an object, and has nothing particularly to do with its structure. Entirely smooth surfaces banded in different colors have a "spatial frequency". Extremely irregularly surfaces have no effective spatial frequency. Objects on the same scale as, say, a human head, would have to be "rubbed" at ridiculous high rates (and repeatedly) to even get into a "frequency" range that might include pressure variations that would be considered as a "wave".
I think you're imagining an entirely too limited set of objects.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by fzeindl on Sunday February 22, 2026 @02:42AM
(#47109117)
In the book „the design of everyday things“ it is mentioned that „natural mappings“ exist. Moving the knob of a vertical slider to the upper end universally means „brighter“ or „louder“, not „less bright“ or „more silent“.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by 5- on Sunday February 22, 2026 @04:23AM
(#47109612)
maybe the chicks and norman get it, but i'm currently renting an apartment in france that has a bunch of these light switches installed all upside down, with "-" at the top:
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by jaffa2 on Saturday February 21, 2026 @08:05PM
(#47106973)
I think it’s natural to think of this in terms of frequencies so the kiki shape has a higher visual frequency. As does the word have a higher audio frequencies within in than bouba so that is naturally associated with the lower frequency undulating line of that shape.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by a115ltd on Saturday February 21, 2026 @06:11PM
(#47105972)
This is just one micro-instance of a much larger thing. Brain encodes structural similarity across modalities. Corollary: language is far from arbitrary labels for things.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by andrewflnr on Saturday February 21, 2026 @07:51PM
(#47106862)
No, language is still pretty close to arbitrary labels. The handful of tenuous common threads like the bouba-kiki effect don't change the overall picture that much. The simple fact that language varies as much as it does is sufficient to prove that it's only loosely bound to anything universal.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by suddenlybananas on Saturday February 21, 2026 @06:34PM
(#47106245)
>language is far from arbitrary labels for things
I think this is a misunderstanding of the arbitrariness of the sign. Arbitrary doesn't mean "random" or "uniformly sampled." The fact there are systematic tendencies among languages in how things are called doesn't negate the arbitrariness of the sign, they could have been called other things. We can also decide to refer to things by another name and we can use any arbitrary name we like! There is no limits on what names we can use (besides silly physiological constraints like having a word with 50 000 consonants). But, of course, there's much more to language than just labels!
For me, the interesting thing in this paper vis-à-vis language is that it shows how much innate structure in cognition must shape our language.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by naniwaduni on Saturday February 21, 2026 @08:02PM
(#47106955)
Arbitrariness of the sign is a principle that requires so many epicycles to present as "true" that it's more of a warning against overgeneralization than an insight with any significant predictive power in its own right.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by suddenlybananas on Sunday February 22, 2026 @03:45AM
(#47109438)
Let's call the arbitrariness of the sign, blinga. Why do you think blinga requires "epicycles"? Blinga makes pretty modest claims: there is no requirement that the form of a sign matches that which it signifies in any way.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by selridge on Saturday February 21, 2026 @09:15PM
(#47107432)
The published one repeated the experiment w/ day old chicks and IIRC the same number w/ the same results, so it's got a little more N than the preprint.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by goodJobWalrus on Saturday February 21, 2026 @07:12PM
(#47106566)
I looked it up, according to Google:
This phrase is a direct quote from the 1955 play (and 1960 film) Inherit the Wind, spoken by the character Henry Drummond (based on Clarence Darrow) regarding the teaching of evolution. It frames scientific education and intellectual freedom as the ultimate, pure progress of human civilization, contrasting with dogmatic resistance.
Context: The line refers to the 1925 Scopes "Monkey" Trial, which debated the legality of teaching evolution in Tennessee schools.
Significance: It serves as a dramatic defense of modernism, science, and freedom of thought against traditionalist views.
Cultural Impact: While based on historical events, the play uses this line to argue that intellectual inquiry is the cornerstone of advancement.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by AreShoesFeet000 on Sunday February 22, 2026 @08:52AM
(#47111001)
This is irony. The study is stupid, society has reached a stupid stage of development. Kiki and bouba explain nothing and serve nothing. Culture is in shambles.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by keyle on Saturday February 21, 2026 @09:56PM
(#47107669)
I'm not entirely sold by this discovery. For example when you learn to train dogs, you learn about the 3 voices. Encouraging voice, atta boy, negative voice, more stern, and the big "NO!".
To some degree these words type sounding language are doing the same thing. Some sounds will irk, some will soothe, and it would affect this 'evidence' found.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by spagettnet on Sunday February 22, 2026 @01:17AM
(#47108698)
I think the researchers agree with your premise. The “evidence” is not that chicks have more language understanding than previously understood, but rather that the source of the universality of bouba/kiki is due to something more primitive than built in human language hardware.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by bad_username on Sunday February 22, 2026 @03:10AM
(#47109272)
Objects that have sharp edges generate higher frequency harmonics when agitated, because lower-size features resonate on higher frequencies (like shorter strings ring on higher pitch). Objects that are round resonate on low frequencies only. The "kiki" sound has more high frequency content than the "bouba" sound, and it's no mystery why the brain associates one with the other.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by rcxdude on Sunday February 22, 2026 @06:26AM
(#47110157)
It's a hypothesis. How would you prove or disprove that it's because of that? (and I would say, a priori, it's not utterly obvious that the brain would relate spacial and temporal frequencies like this)
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by PaulDavisThe1st on Sunday February 22, 2026 @10:15AM
(#47111654)
Some of the research, including this paper, is trying to get at the question of whether a species' sensitivity to the bouba-kiki effect might be at the root of language or not. Since it seems accepted that chickens do not have language in any meaningful sense of that term, finding that they still show this effect decouples it from "the origins of language".
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by PaulDavisThe1st on Tuesday February 24, 2026 @01:41PM
(#47140856)
bouba-kiki has been previously shown not to exist for some set of other primates. given the general sense that they are closer to some form of language than baby chickens, its presence in the latter and absence in the former would suggested that it is not necessary.
all this research could be deeply flawed, however.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by magneticnorth on Sunday February 22, 2026 @12:39PM
(#47112921)
Hollow things are common, and of interest to many animals. If I thump a log and it makes a noise like it has a hollow space (low tones), then it may contain an animal nest or a beehive & honey, or it may be something I could use as a box or basket or shelter.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by ASalazarMX on Monday February 23, 2026 @02:59PM
(#47127884)
Maybe animal sounds count? Warning sounds tend to be loud, sharp, and high-pitched; and when ignored, they might end with more material sharp things in your skin. I can't recall any animal with a soft warning sound.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by GuB-42 on Sunday February 22, 2026 @09:43AM
(#47111386)
That's one theory. Another one I can think of is that sharp edges are scary, and most distress calls are high pitched.
Also, the thing about high frequencies and sharp edges lead to a contradiction: babies are more round than adults and produce higher pitched sounds, this is almost universal across all species.
There are other tentative explanations, such as how the vocal tract acts when producing these sounds, with "bouba" sounds being the result of smoother movement more reminiscent of a round shape.
"kiki" is not just higher pitched, it is also "shaped" differently if you look at the sound envelope, with, as expected, sharper transitions.
So to me, the mystery is still there. Is is the kind of thing that sounds obvious, in the same way that kiki sounds obviously sharper than bouba, but is not.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by scrumper on Sunday February 22, 2026 @01:38PM
(#47113465)
> Also, the thing about high frequencies and sharp edges lead to a contradiction: babies are more round than adults and produce higher pitched sounds, this is almost universal across all species.
It's more in terms of harmonic content than the pitch fundamental. There are more harmonics from a thing with sharp transitions than there are in a thing with rounded transitions regardless of the fundamental pitch. Compare harmonic content of a pure sine wave (it's just the fundamental) with that of a square wave, which has an infinite series of higher harmonics.
Babies are also smaller, which means higher fundamental pitch.
> "kiki" is not just higher pitched, it is also "shaped" differently if you look at the sound envelope, with, as expected, sharper transitions.
Exactly!
EDIT I think this is interesting: it also applies to images as well, not just sound. You can "low pass filter" a photograph and it'll reduce some of the detail, smoothing out transitions (typically used for noise reduction). Detail is high frequency information (or high frequency noise depending on whether you want it or not.)
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by saalweachter on Sunday February 22, 2026 @03:08PM
(#47114162)
So you know the "bock bock" sound?
Hens make it occasionally when laying eggs, but it's also the rooster alarm sound. The "cock-a-doodle-doo"/crowing sound is more the all-clear/I'm-a-rooster-here-I-am/flock-assemble cry.
When there's a threat, the rooster switches to a loud, BAWK BAWK BAWK alarm.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by littlestymaar on Sunday February 22, 2026 @02:39PM
(#47113938)
> The "kiki" sound has more high frequency content than the "bouba" sound
And where did you get that from?
In non-tonal languages the pitch conveys almost no information and people speak at very different ones (and for instance a male saying "kiki" will say it at lower frequencies than a woman saying "bouba" most of the time) so I find your affirmation very dubious.
> and it's no mystery why the brain associates one with the other.
Specialists of the field find that mysterious but some smartass on HN disagrees.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by IAmBroom on Monday February 23, 2026 @01:07PM
(#47126169)
> > The "kiki" sound has more high frequency content than the "bouba" sound
> And where did you get that from? In non-tonal languages the pitch conveys almost no information and people speak at very different ones (and for instance a male saying "kiki" will say it at lower frequencies than a woman saying "bouba" most of the time) so I find your affirmation very dubious.
You misunderstand the post. It has nothing to do with the voice of the speaker.
Long drawn-out sounds have lower frequency components than short-lasting sounds. A pin drop is REALLY high-pitched; a moan has at least some low-pitch components (but may still be high-pitched, too - more often called a "keening" than a moan). It's not about intonation; it's a mathematical consequence of the relationship between frequency and time-domain incidents, typically measured with Fourier transforms.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by Strilanc on Sunday February 22, 2026 @03:18AM
(#47109307)
For each chick they do 24 trials divided into 4 blocks with retraining on the ambiguous shape and actual rewards after each block. During the actual tests they didn't give rewards. In figure 1 they show the data bucketed by trial index. It's a bit surprising it doesn't show any apparent effect vs trial number, e.g. the first trial after retraining being slightly different.
I have to admit I'm super skeptical there's not some stupid mistake here. Definitely thought provoking. But I wish they'd kept iteratively removing elements until the correlation stopped happening, so they could nail down causation more precisely.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by rubidium on Sunday February 22, 2026 @02:47PM
(#47113997)
I do agree my skepticism level rises extremely high in any experimental psychology experiment. There’s just so many ways to bias results, in addition to “do enough experiments and one of them will get a statistically unlikely result” problem.
This group does a lot like this https://www.dpg.unipd.it/en/compcog/publications … so that’s tempting to think they keep trying things until something odd happens (kind of like physicists who look for 5th forces… eventually they find something odd but often it’s just an experimental issue they need to understand further).
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by crazydoggers on Sunday February 22, 2026 @10:11AM
(#47111621)
Very likely this experiment suffered from a lack of thorough double blind control. Researcher bias may have generated subtle subconscious queues to the chicks on which shape to pick unrelated to the sounds.
Re:Evidence of the bouba-kiki effect in naïve baby chicks
by bondarchuk on Tuesday February 24, 2026 @06:12AM
(#47135674)
I see several people say primates don't show the effect, however all tests on primates were done with a "language-competent bonobo" and "touchscreen trained chimpanzees (N=6) and gorillas (N=2)" that are first trained to do various language/picture association tasks and then tested like how you'd test humans. It would be interesting to test primates using the same methodology they used here on chickens. The previous language/computer training in the monkeys might have interfered with a more low-level/intuitive bouba-kiki effect.
But I guess it's about why so we associate those with spiky shapes, though surely it's because they represent sharp immediate changes in frequency?
I'd be interested on results of shapes imagined when you take the source as musical or other non speech sounds.
I think the why just got a lot tricker than we imagined. Because we failed to replicate this experiment on other primates, we couldn't avoid a semantic suspicion about those associations. Now we probably have to set semantics aside or let it get a lot weirder, because we can replicate across ~300My.
>surely it's because they represent sharp immediate changes in frequency?
Maybe, and I think "multi-sensory signal processing" is the best framing, but the representation could also carry harder to think about things like "harm".
It's also super cool because the bouba-kiki effect framing was chosen due to methodological convenience for linguists and cultural anthropologists and their experimental bounds, not neuroscientists or signal processing folks. We could potentially find other experiments quickly, since chicks are a model organism and the mechanism is clear.
Things could move fast here.
Sure, but it's a very abstract connection between objects being sharp in vision and frequencies changing sharply in hearing. There's no guarantee any given organism would make the connection.
I think you're imagining an entirely too limited set of objects.
https://www.legrand.com.gh/en/catalog/products/arteor-push-b...
Except for the organ drawbars?
I think this is a misunderstanding of the arbitrariness of the sign. Arbitrary doesn't mean "random" or "uniformly sampled." The fact there are systematic tendencies among languages in how things are called doesn't negate the arbitrariness of the sign, they could have been called other things. We can also decide to refer to things by another name and we can use any arbitrary name we like! There is no limits on what names we can use (besides silly physiological constraints like having a word with 50 000 consonants). But, of course, there's much more to language than just labels!
For me, the interesting thing in this paper vis-à-vis language is that it shows how much innate structure in cognition must shape our language.
> We tested a total of 42 subjects, 17 of which were females.
This phrase is a direct quote from the 1955 play (and 1960 film) Inherit the Wind, spoken by the character Henry Drummond (based on Clarence Darrow) regarding the teaching of evolution. It frames scientific education and intellectual freedom as the ultimate, pure progress of human civilization, contrasting with dogmatic resistance.
Context: The line refers to the 1925 Scopes "Monkey" Trial, which debated the legality of teaching evolution in Tennessee schools.
Significance: It serves as a dramatic defense of modernism, science, and freedom of thought against traditionalist views.
Cultural Impact: While based on historical events, the play uses this line to argue that intellectual inquiry is the cornerstone of advancement.
To some degree these words type sounding language are doing the same thing. Some sounds will irk, some will soothe, and it would affect this 'evidence' found.
It must take some strange things to survive co-evolution with humans for several thousands years
all this research could be deeply flawed, however.
Thump a round club/log against a rock -> dull bump noise
Thump pointy branch against a tree -> dull noise
And chickens aren't using tools.
In your example it's obviously the round tree trunk that produces the dull sound.
E.g. a spider does not learn if/how to weave a web from its parents.
Also, the thing about high frequencies and sharp edges lead to a contradiction: babies are more round than adults and produce higher pitched sounds, this is almost universal across all species.
There are other tentative explanations, such as how the vocal tract acts when producing these sounds, with "bouba" sounds being the result of smoother movement more reminiscent of a round shape.
"kiki" is not just higher pitched, it is also "shaped" differently if you look at the sound envelope, with, as expected, sharper transitions.
So to me, the mystery is still there. Is is the kind of thing that sounds obvious, in the same way that kiki sounds obviously sharper than bouba, but is not.
It's more in terms of harmonic content than the pitch fundamental. There are more harmonics from a thing with sharp transitions than there are in a thing with rounded transitions regardless of the fundamental pitch. Compare harmonic content of a pure sine wave (it's just the fundamental) with that of a square wave, which has an infinite series of higher harmonics.
Babies are also smaller, which means higher fundamental pitch.
> "kiki" is not just higher pitched, it is also "shaped" differently if you look at the sound envelope, with, as expected, sharper transitions.
Exactly!
EDIT I think this is interesting: it also applies to images as well, not just sound. You can "low pass filter" a photograph and it'll reduce some of the detail, smoothing out transitions (typically used for noise reduction). Detail is high frequency information (or high frequency noise depending on whether you want it or not.)
Hens make it occasionally when laying eggs, but it's also the rooster alarm sound. The "cock-a-doodle-doo"/crowing sound is more the all-clear/I'm-a-rooster-here-I-am/flock-assemble cry.
When there's a threat, the rooster switches to a loud, BAWK BAWK BAWK alarm.
Formulating theories is all nice and dandy, but it ain't science.
Does the original paper (I couldn't find it in the article) explore this a bit more ?
It's actually nice if the effect can be studied on chickens, they are definitely less expensive and more plentiful than human babies.
Formulating theories ain't the whole of science, but it's a big part of it.
And where did you get that from? In non-tonal languages the pitch conveys almost no information and people speak at very different ones (and for instance a male saying "kiki" will say it at lower frequencies than a woman saying "bouba" most of the time) so I find your affirmation very dubious.
> and it's no mystery why the brain associates one with the other.
Specialists of the field find that mysterious but some smartass on HN disagrees.
> And where did you get that from? In non-tonal languages the pitch conveys almost no information and people speak at very different ones (and for instance a male saying "kiki" will say it at lower frequencies than a woman saying "bouba" most of the time) so I find your affirmation very dubious.
You misunderstand the post. It has nothing to do with the voice of the speaker.
Long drawn-out sounds have lower frequency components than short-lasting sounds. A pin drop is REALLY high-pitched; a moan has at least some low-pitch components (but may still be high-pitched, too - more often called a "keening" than a moan). It's not about intonation; it's a mathematical consequence of the relationship between frequency and time-domain incidents, typically measured with Fourier transforms.
I have to admit I'm super skeptical there's not some stupid mistake here. Definitely thought provoking. But I wish they'd kept iteratively removing elements until the correlation stopped happening, so they could nail down causation more precisely.
This group does a lot like this https://www.dpg.unipd.it/en/compcog/publications … so that’s tempting to think they keep trying things until something odd happens (kind of like physicists who look for 5th forces… eventually they find something odd but often it’s just an experimental issue they need to understand further).
References here https://evolang.org/jcole2022/proceedings/papers/JCoLE2022_p...