A newborn's cry is a call to action. "Quick, somebody help me!" But bawling babies are getting something else besides attention: language practice. A new study finds that, in the first few days of life, babies produce cries that mimic the melodies of their native language.
By the time a baby is born, it's been learning about the outside world for a long time. In the last 3 months of gestation, a fetus's ears have developed enough to pick up sounds, including its mother's voice. This may explain why newborns--babies up to 1 month old--already seem to prefer being talked to in their native tongue. By 4 months or so, babies have a lot of outside-the-womb experience--and a better-developed vocal tract. That's when they start babbling in their parent's language or languages. But researchers didn't believe that babies could make native-language-specific sounds before this age.
Behavioral scientist Kathleen Wermke of the University of Würzburg in Germany suspected otherwise. She's been studying babies' cries for 2 decades and has seen, for example, that children whose cries have more complex melodies and rhythms at 2 months of age have more developed language skills later. "I think cry melody is really the beginning of language development," Wermke says. Her new study backs that up.
Wermke and colleagues analyzed digital recordings of cries from 30 German and 30 French babies who were between 2 and 5 days old. All of the crying was spontaneous; no babies were harmed in the making of this study. The researchers analyzed melody contour--whether the cries tended to rise from lower pitches to higher pitches or to fall from higher pitches to lower pitches.
All of the infants tried out their vocal repertoire with a wide variety of cries, the scientists report online today in Current Biology. But French babies produced more cries with a rising contour, whereas German babies produced more falling cries. These melodies are typical of the speech patterns of their respective languages, the team reports.
The findings indicate that newborn infants are already making sounds that are precursors to the sentences they'll be saying in a few years, says Wermke. That makes perfect sense, she says. "Why should a baby wait for 4, 5, 6 months before starting this language development?" Wermke thinks babies learn the melody of the language in utero, although it's impossible to rule out that they're showing the results of very rapid learning since birth.
"My mouth was kind of hanging open as I was reading," says Janet Werker, a developmental psychologist at the University of British Columbia in Canada. Researchers knew that "[newborns] can hear the difference between things, they have a preference for their mother's voice, but to show that it's actually affecting their cry production is pretty stunning." She points out that it's particularly impressive that infants apparently have some control over their vocalizations, an ability some older studies suggested that newborns lacked.
Wermke says the next step is to compare cries from other language backgrounds, like Chinese and Japanese. She would also like to look at hearing-impaired infants to see how their cries differ. She says the study is a reminder that language does not start with the first words, or even the first syllables. Newborn infants may look like tiny blobs who do nothing but sleep, eat, and cry, but they're already warming up for a lifetime of talking.