‘Mind-blowing’ baby chick study challenges theory of how humans evolved language
Newborn chicks associate sounds with shapes just like humans do, suggesting deep evolutionary roots of the “bouba-kiki” effect.
Huizeng Hu/Getty Images (photography); Jeffrey Delvisio (Picture)
Why is the sound of “bouba” round and the sound of “kiki” is spiky? This intuition that connects certain sounds to shapes is strangely reliable throughout the world and for at least a centuryScientists consider this a clue to the origins of language, theorizing that perhaps our ancestors formed their first words on these intuitive connections between sound and meaning. But now a new study adds an unexpected twist: Baby chickens make similar sound-shape connections, suggesting that the link to human language may not be so unique.
Result, Published today in ScienceChallenge a long-standing theory about the so-called Bouba-Kiki effect: It could explain how humans first linked sound with meaning to create language. Perhaps, the thinking is that people naturally agree on certain relationships between shapes and sounds because of some innate feature of our brain or our world. But if even the barnyard hen agrees with such associations, you might wonder whether we are sowing the wrong linguistic seeds.
Maria Loconsola, a comparative psychologist at the University of Padua in Italy, and her colleagues decided to investigate the Bouba-Kiki effect in chicks because the birds could be tested soon after hatching, before their brains were affected by exposure to the world. The researchers exposed chicks to two panels: one showed a flower-like shape with gradual circular rotation; The other had a sharp spot reminiscent of a cartoon explosion. They then played recordings of humans saying “bouba” or “kiki” and observed the behavior of the birds. When the chicks heard “bouba”, 80 percent of them approached the round shape first and spent an average of more than three minutes searching for it, while searching for the spiky shape took an average of less than a minute. When the chicks heard “kiki”, exploration priorities were reversed.
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Because the tests took place in the chicks’ first hours of life under careful observation outside the eggshell, this association between particular sounds and shapes could not be learned from experience. Instead it may be evidence of an innate perceptual bias that goes much further back in our evolutionary history than we realize.
“We separated from birds on the evolutionary line 300 million years ago,” says linguist Aleksandra & Cacutewicz of Nicolaus Copernicus University in Toruń, Poland, who was not involved in the study. “It’s absolutely mind-blowing.”
Ćwiek and colleagues in a 2022 paper Exhibited The Buba-Kiki effect applies to various cultures and writing systems around the world. Other experiments have shown that humans infants perform similarly On these tests, even before they learned to speak. And in 2019 and 2022 researchers tested the effect in great apes and found that they fail bouba-kiki testWhich further strengthened the idea that the effect was exclusive to humans and our linguistic abilities.
Loconsol argues that the apes’ prior communication training may have impaired their performance. Jared Tagliatella, director of the Ape Initiative and co-author of one of the Ape studies, agrees. The study’s subject, Kanzi the bonobo, who recently died, was frequently given similar language-related tests. It is possible that when Kanji encountered these new nonsense words, he tried to guess their “meaning” rather than following his intuition.
In light of the new chick discoveries, Ćwiek has also taken a broader approach. She says, “It actually makes the question of Bouba-Kiki less interesting as a solution to language evolution because it is prelanguage.” “I think it shows us something deeper about cognition, about the ability to connect the senses.”
As for what on earth makes “bouba” round and “kiki” spiky, we may be able to debunk a long-standing theory: that these relationships are driven by the shape of your mouth when you say each word. While the “b” sound requires rounding your lips, and the “k” sound requires an explosive tap on the roof of your mouth, chickens apparently can’t utter them at all. The Bouba–Kiki effect may instead arise from the physical properties of the objects themselves, As some researchers have suggested. When round objects hit or roll along the ground, they generally produce more sustained, low-frequency sounds than spiky objects. The underlying understanding of those dynamics, combined with sight and sound, may help newborn animals quickly sense their environment, potentially locating food or avoiding predators.
The Bouba–Kiki effect may have played a role in the emergence of language, along with many other cognitive abilities. But for chickens (and possibly other animals), these same predispositions appear to serve a more evolutionarily ancient purpose. “Even though language is unique to humans,” Loconsol says, “that doesn’t mean it comes from humans. an ability This is unique to humans.”
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