Goodnight, buenas noches: Foreign language lullabies help babies relax too

CAMBRIDGE, Mass. — Music has always had the ability to bring people together and bridge the gap between cultures, languages, and countries. Now, a new study finds that even infants can appreciate a good lullaby sung in a foreign language. Researchers at Harvard University reveal American babies still relax after being played unfamiliar lullabies sung in other languages.

“There’s a longstanding debate about how music affects listeners as a result of both prior experiences with music and the basic design of our psychology,” says Samuel Mehr, the principal investigator from Harvard’s Music Lab, in a university release. “Common sense tells us that infants find the lullabies they hear relaxing. Is this just because they’ve experienced their parents’ singing before and know it means they’re safe and secure? Or is there also something universal about lullabies that produces these effects, independently of experience?”

This research validates the theory that babies respond to something universal in lullabies that naturally evokes feelings of calm and sleepiness, regardless of whether they’re familiar with the actual words in the song.

Relaxation is a universal concept

To start, each baby viewed a cartoon of two characters singing either a lullaby or a non-lullaby. At the same time, researchers gauged the babies’ subsequent relaxation responses to the cartoon by measuring pupil dilation, heart rate changes, frequency of blinking, electrical skin resistance, and gaze direction.

While listening to unfamiliar lullabies, babies experienced drops in heart rate and pupil dilation and a stabilization of electrodermal activity.

Study authors say they would have performed a longer experiment, but the attention span of a baby limits their abilities. A typical baby can only really focus on one thing for about five minutes before becoming distracted.

“In an ideal world, we would play babies a dozen songs that are lullabies and a dozen songs that are not lullabies and gather a lot of data from each infant. But an infant’s attention span is short, so the experiment is short too,” explains co-first author Mila Bertolo.

Songs and lullabies included in this study incorporated a host of different languages, including Hopi, Scottish Gaelic, and Western Nahuatl. Researchers made sure to represent various regions and continents, like the Middle East and Central America.

“Melody is one of the things that sticks out for lullabies. In comparison, in a lot of other song types, such as dance songs, you would see rhythm as being more of a driving force,” adds study co-leader Connie Bainbridge.

Forget the babies. Can foreign lullabies have the same impact on adults?

At one point, researchers asked the participant’s parents to listen to two unfamiliar songs and decide which one would be more soothing for their baby. Nearly every single time the parent chose a lullaby. This suggests there are certain universal, calming elements in lullabies across cultures that the mind recognizes on a subconscious level.

“Calming a fussy infant is an urgent matter for parents. Those of us with kids might be particularly sensitive to the acoustic features that appear universally in lullabies, as these may be most likely to calm our infants efficiently,” Mehr says.

The research team believes their work shows the power and effectiveness of music on human mood. They also wonder if the same results could apply to adults as well. Similarly, researchers theorize the same experiment conducted with a group of babies born in another nation would yield similar findings.

Moving forward, the team at Harvard wants to continue investigating this topic. For example, is there a way to enhance the tranquil effect of lullabies?

“While the music in general was relaxing, there was something about the lullabies that was especially relaxing, so in theory there could be ways to optimize the music we provide to infants, to make them more effective,” Bainbridge concludes. “Additionally, it’s an interesting area to explore as far as the function of music — is it an adaptation that we evolved to have or a byproduct of language or auditory cognition? Our findings do seem to support the idea that there is actually an evolutionary function of music.”

The study is published in Nature Human Behaviour.