Lullabies strike a chord: Singing to babies strengthens Bonds and boosts development

By Dr. Liji Thomas, MDReviewed by Benedette Cuffari, M.Sc.Jun 21 2023

Throughout the world, singing lullabies and other songs to babies is a common and enjoyable practice that promotes parent-infant bonding. However, the lack of solid evidence to support these beliefs prompted a recent study published in Infant Behavior and Development.

Study: The effects of live parental infant-directed singing on infants, parents, and the parent-infant dyad: A systematic review of the literature. Image Credit: fizkes / Shutterstock.com

Introduction

Singing to babies is likely as common as speaking, murmuring, or other forms of vocalization and has an equal or more powerful impact on distressed, hungry, or lonely babies.

Babies may also express their needs and desires through non-verbal sounds that are difficult for parents to ignore. Thus, the parent-infant bond is created based on these communications, thereby strengthening the degree of attachment felt by the baby for the parents.

The current study focuses on infant-directed singing (IDSg) as a primary mode of communication within the parent-infant pair. IDSg includes a melody with an identifiable tempo, pitch, and repetitive elements, with or without lyrics, that is directed toward the infant rather than an adult. Typically, IDSg is slower and at a higher pitch than ordinary singing, even with the same songs.

Infants pay more attention to IDSg rather than adult-directed singing between four and seven months of age. This preference may become weaker or disappear by one year of age.

Prior research has demonstrated lower levels of postnatal maternal depression with daily IDSg, in addition to a better sense of well-being and self-esteem. This could be due to a sense of enjoyment of the musical sounds themselves, the sense of interacting positively with the baby, the act of singing, and one’s personal reaction to the song.

When infants feel that their needs are being met, and their parents feel successful in meeting these needs, the relationship itself is strengthened.”

The current study sought to identify the developmental period during which IDSg has the greatest impact on infants from birth to 1.5 years of age and how this may impact infant development.  

What did the study show?

This systematic review included 21 studies, most of which were quantitative in nature, including four to 391 dyads. However, the median sample size was relatively small, at 31.

In almost all cases, the parent involved was the mother, and non-parental caregivers were not represented at all.

Most studies included healthy term babies; however, preterm babies were separately considered in the review and categorized as healthy preterm or preterm with brain injury. A separate class was created for babies with Down syndrome between three and nine months of age.

Term babies were assessed behaviorally at home, in a lab, or online. In contrast, preterm babies were generally in hospital, and physical or physiological responses were mapped.

Impact of IDSg on infants

Better emotional regulation was observed in infants exposed to IDSg. In fact, different songs were used to manipulate the state of arousal of the infants, whether active and alert or calm and relaxed.

As judged by body movements, sounds made, attention, and mood, IDSg produced multiple effects depending on why the song was being sung. For instance, babies became calm, went to sleep, or were distracted. IDSg typically reduced body activity and induced quietness, less vocal sounds, or more smiles, thus indicating a positive mood alteration.

The impact of IDSg in the preterm group was less homogeneous. In preterms, some studies reported greater physiological instability, with higher heart rates and increased oxygen saturation.

Infant distress was most effectively reduced by familiar songs, followed by unfamiliar songs. Cortisol levels dropped if already high, but increased towards normal if unduly low at baseline, thereby indicating that IDSg normalizes stress levels as required to regulate the infant’s physiology.

IDSg is associated with reduced crying time and active sleep in preterm infants, whereas this type of singing is associated with quiet attentiveness in term infants. Nighttime awakenings were less stressful and far less frequent in infants sung to during pregnancy and after birth.

Overall, IDSg appears to help infants achieve better emotional regulation by helping infants relax, pay attention, feel happy, or become ready for sleep.

For example, infants were found to attend better to the mother’s singing, as demonstrated by them making fewer sounds as compared to when she is speaking to them. In preterm infants with severe brain injury, singing producing more instability in the child’s bodily processes and behaviors.

Impact of IDSg on parents

Parents felt validated with IDSg because it built their confidence that they were able to read and respond to their infant’s needs, help the baby learn and grow, and feel better as mothers.

Mothers perceive their use of IDSg as helping them care for their babies properly by themselves. This form of singing also helps mothers identify their child’s needs and fulfill them rightly.

By helping to provide this feeling of confidence and ability towards providing care for the infant as the primary caregiver, IDSg fulfills a role as an essential parenting tool.

IDSg also helps mothers teach babies about their culture and promotes language skills, thus building the mother’s role as an educator. Enhanced maternal well-being, self-esteem, bonding, and lower depression, stress, and anxiety are other benefits have been observed in IDSg to parents.

Impact of IDSg on the dyad

IDSg helps parents and children grow stronger in their bond and attachment by sharing a common experience, responding to each other, and connecting in a positive way with the other person at the same time.

During IDSg, parents’ moods were reflected in that of their babies. Moreover, the response of the infant to the music is typically based on the beats stressed by the parent, thus indicating a simultaneous experience.  

What are the implications?

IDSg has an important role in promoting infant development, helping the infant self-regulate, encouraging mutual responsiveness, building the dyadic bond, and validating the parent as a caregiver.

Interestingly, studies in which the parent could choose the song showed a more significant impact, perhaps because this allowed parents to recognize and respond to their child’s mood by the choice of song, limiting the interaction.

Ultimately, IDSg by parents communicates social and emotional information a that teaches infants about themselves, their family, and the world around them.”

In preterm infants who are often not strong enough to be handled by the caregivers, IDSg could be used to build and sustain a strong parent-infant bond and promote attachment between them.

Additional research is also needed to extend these findings to other caregivers, such as early childhood educators, infant caregivers at daycare centers, and hospital therapists.