Article image
12-11-2021

Maternal chemical signals help infants bond with strangers

A new study led by the Center of Developmental Neuroscience at Reichman University, Israel, has found that chemical signals in mothers’ body odor may have a significant role in supporting the development of infants’ social brains and make them capable of interacting with strangers from an early age.

While maternal body odors serve as important safety-promoting and social recognition signals, their role in human brain maturation has been largely unknown. A research team led by Yaara Endevelt-Shapira, a postdoctoral research associate at the Center for Developmental Neuroscience, has recently investigated in more detail the complex role of chemical signals in enhancing infant-adult brain-to-brain synchrony.

The scientists gave 62 mothers a cotton t-shirt each and asked them to use it as a pajama for two consecutive nights before the experiment. In a first stage of the empirical study, the mothers and their infants had electrodes placed on their heads and were seated initially back-to-back, then face-to-face. When they were facing each other, mothers and infants shown higher neural synchrony.

In a second stage of the experiment, 51 of the infants were seated face-to-face with a stranger – a woman with a similar age as their mothers who lived in a nearby area and had an infant of about the same age. While the infants interacted with this woman, they were exposed to either a clean t-shirt or the t-shirt that their mother used.

Infants who were exposed to a clean t-shirt showed a significantly lower inter-brain neural synchrony with the stranger than with their mother. By contrast, those exposed to the t-shirt with their mother’s body odor showed the same degree of neural synchrony with the stranger as with their mother. 

These findings suggest that scent preserves a chemical signal of the mother’s presence even in her absence, increasing the infants’ social capabilities and helping them survive in a constantly changing social environment.

“Human mothers use interbrain mechanisms to tune the infant’s social brain, and chemosignals may sustain the transfer of infant sociality from the mother-infant bond to life within social groups,” the authors concluded.

The study is published in the journal Science Advances.

By Andrei Ionescu, Earth.com Staff Writer

News coming your way
The biggest news about our planet delivered to you each day
Subscribe