Music and singing are some of the most common forms of social interaction and play during early childhood. Caregivers all over the world sing to their infants to engage or soothe them. Seemingly simple acts, like singing to and engaging in musical games with young children, can profoundly impact children, caregivers, and their relationship with each other.
Singing to infants is highly effective at capturing and maintaining children’s attention. In fact, young infants pay attention longer when someone sings to them than when someone speaks to them. Singing is also more effective than speaking at calming infants down when they are upset (bonus: it calms down caregivers, too!). Caregivers report feeling closer to their infants when they sing to them.
But why does singing to infants have such powerful effects on infant and caregiver behavior and connection? Our recent study, published in the Proceedings of the National Academy of Sciences, reveals that the predictable rhythm of singing is critical for supporting the developing social relationship between caregiver and infant.
When we sing to infants, our songs tend to have a clear rhythmic structure with alternating strong and weak beats (i.e., what you clap your hands or tap your foot to when listening to music or singing your baby’s favorite nursery rhyme). These beat-based musical rhythms help people synchronize their behavior with each other, like when the audience all claps in time together at a concert, which makes people feel more socially connected.
When rhythmic synchronization is studied in adults, researchers often use tasks like tapping, clapping, or even dancing together. But infants don’t have control over these types of arm and leg movements. Instead, to study rhythmic synchronization to singing in infants, we examined infants’ eye movements because eye contact is an essential form of social communication beginning in infancy. We used eye-tracking technology to study infants’ moment-by-moment eye-looking when they viewed videos of actresses engaging them with songs like "Twinkle, Twinkle Little Star" and "Mary Had a Little Lamb."
As early as two months of age, when infants are first engaging with others in an interactive manner, infants were two times more likely to look to the singers’ eyes time-locked to the musical beat than would be expected by chance. By six months of age, when infants are highly experienced in face-to-face musical games and are developing increasingly sophisticated rhythmic and communicative behaviors like babbling, they are more than four times as likely to look to the singers’ eyes synchronized to the musical beats. Though infants could look anywhere on the video screen, their looking behavior was not random: Infants preferentially looked at the singers’ eyes at the rhythmically important moments.
We also wanted to examine why infants would look at the singers’ eyes on the musical beats. Do singers change their behavior at the beats in a way that is particularly important or interesting for infants? After all, infants don’t look for no reason! It turns out that singers also synchronized their facial expressions to their own singing. Singers were more likely to provide positive, engaging facial expressions on the beats than between them.
So wait, you might be thinking, is it really rhythm that matters, or are infants just responding to the singers’ facial expressions? To test this, we repeated the study with another group of 6-month-old infants who watched the original singing videos, as well as videos that were experimentally manipulated so that the rhythmic structure was no longer predictable. During the natural, rhythmically predictable singing, infants were again more likely to look at the singers’ eyes synchronized to the beats, but they were no longer able to do so when the rhythm was disrupted. Although what a singer expresses is important, when and how they express social cues is particularly critical for infant-caregiver communication.
Young infants’ attentional, motor, and communication skills are still developing, so it is incumbent on the caregiver to structure their interactions so that infants can actively engage with them. Rhythmic predictability is a universal feature of song, and singing to infants is a highly intuitive act that caregivers generally do without receiving any explicit instruction. It turns out that when caregivers sing to their infants, caregivers are naturally providing structure to support infants’ social learning and the infant-caregiver social bond.
Ideas for incorporating singing in your everyday play and interactions with your infant:
- Follow your child’s cues during songs and musical games; pay attention to your child’s gaze, movements, and vocalizations to guide you in how energetically or calmly to sing.
- Emphasize the rhythm of the song by stressing the words on the beats; you can also add movements and gestures like bouncing your baby to the beat of the music, nodding your head, or clapping your or your baby’s hands.
- Find a few minutes each day to get face-to-face with your child when singing to them to be sure they can see all the social cues provided in your face as you engage them with the song.
- Pause at the end of a song phrase and see if your child communicates in any way—such as by looking at you, moving or gesturing, or vocalizing a sound—to indicate that they want you to continue singing.
- Sing songs that are meaningful to you and to your baby! Traditional nursery rhymes like "Twinkle, Twinkle Little Star" and "Pat-a-Cake" have stood the test of time for being of interest to infants and caregivers. But also choose songs that are culturally or personally meaningful to you for building your own family musical traditions.
