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A newborn baby in a pink hat and mittens.
Even 2-day-old babies know that some syllables just sound better than others, according to a new study.

Across world languages, certain syllables are more commonly used than others. But why this linguistic preference exists has been a matter of scientific debate. While some researchers have suggested that the preference results from the historical processes that shape languages, or the ease of pronunciation, others hold it may be innate, with the human brain being partial to certain sounds.

Now, the new study suggests that people are indeed born with a preference for some sounds over others.

"We believe that many things are learned, for instance, the vocabulary," said study author David Maximiliano Gómez, a language and cognition researcher at the University of Chile. But there are other aspects of language, such as the syllables people use, that might be innate, he said.

The study, published March 31 in the journal PNAS, shows that babies react to certain syllables very similarly to the way adults do, Gómez told Live Science.

The study was conducted on three groups of 24 Italian babies, ages 2 to 5 days. The children in the study listened to a few kinds of syllables, including "lbif" and "bdif," which are generally less popular among adults, and "blif" and "oblif," which adults more commonly prefer.

The researchers looked at the newborns' brain activity using a neuroimaging method called near-infrared spectroscopy, finding that the babies reacted in the same way that adult brains typically respond to the different types of syllables.

In the babies' brains, the "left temporal cortex reacted in the same way to 'oblif' and 'olbif,' despite reacting in a very different way for 'blif' and 'lbif,'" Gómez said.

Regardless of which language a baby will eventually learn to speak, this sort of brain reaction could offer a benefit, he said. If the newborn has an innate preference for the general patterns shared by many languages, such as the syllable preference, then it will be easier for him or her to learn the details of a language, Gómez said.

"In a way, this innate bias could be a way that infants are better prepared to cope with any language they have to learn," Gómez said.

The preference for certain syllables may also shape languages over time and help to determine which words infants learn earlier than others, he said.

"Even if all adults agreed on calling milk 'lbif,' it's quite probable that our infants would first come up with a modified version of it," such as 'bif,'" he said.