Babies all over the world are what I like to describe as ‘citizens of the world.’ They can discriminate all the sounds of all languages, no matter what country we’re testing and what language we’re using.

Patricia Kuhl, a leading researcher in infant speech perception and language acquisition, has often used the phrase “citizens of the world” when discussing findings from cross-linguistic experiments on babies’ early phonetic abilities. The remark refers to results from laboratory studies in which very young infants (roughly in the first half-year of life) can distinguish many speech-sound contrasts used across the world’s languages, even contrasts not present in the language spoken around them. Kuhl typically contrasts this early, broadly tuned sensitivity with the later “perceptual narrowing” that occurs as infants specialize in the sound patterns of their native language through exposure and social interaction.

Kuhl is summarizing a central finding from developmental psycholinguistics: very young infants begin life with a broadly “universal” sensitivity to human speech sounds, before experience with their home language narrows perception to the phonetic contrasts that matter locally. Calling babies “citizens of the world” emphasizes that early perception is not yet culturally specialized; it is tuned to the full range of possible language sounds. The remark also implicitly points to a time-limited window in which exposure and social interaction shape the brain’s speech categories, helping explain why early immersion can aid later pronunciation and listening. The quote’s significance lies in linking a poetic metaphor to a measurable, cross-cultural experimental result.