If you feel your face turning red when you hear a baby crying, you’re not alone. A study has found that the cries of babies, especially those indicating pain, can indeed trigger flushing and warming of adults’ faces, possibly to grab our attention and prompt us to take action.
Newborn babies cannot speak, so they rely on crying to communicate with their parents or caregivers, expressing their needs for help. However, many new parents often struggle to understand why their baby is crying or differentiate between different types of cries.
In fact, the cry of a baby in pain is different from their other sounds. When babies cry due to pain, they forcefully contract their chest to allow high-pressure airflow through their vocal cords, producing varying tones and discordant sounds, termed as “nonlinear phenomena” (NLP) by acousticians.
To understand how these sounds subconsciously affect the neurological system of adults and the physiological responses they trigger, researchers at the Université Jean-Monnet-Saint-Étienne in France conducted a study.
Biomedical acoustician Lény Lego and colleagues from the university stated that NLP has previously been proven as a reliable indicator of pain or discomfort levels expressed by infants. Their research suggests that the level of NLP modulates the temporal facial heat response of listeners and is unrelated to gender.
In this study, researchers tested the responses of 41 adult participants to infant cries. The participants included 21 males and 20 females with an average age of 35 years.
Participants were presented with 23 recordings from 16 different babies who were crying due to mild discomfort during bathing or pain from vaccination.
Using thermal imaging, the researchers tracked changes in participants’ facial temperature as they listened to the sounds. The increase in facial temperature is a response of the autonomic nervous system. Participants also reported whether they perceived discomfort or pain in the sounds they heard.
The researchers noted that changes in participants’ facial temperature reflected the pain expressed in the infant cries. Cries with higher levels of NLP elicited stronger flushing reactions in participants’ faces. This suggests that these chaotic sounds are more effective at capturing adult attention from a physiological standpoint compared to cries lacking or completely devoid of NLP.
The study revealed that male and female participants responded similarly to cries with high NLP, further confirming the researchers’ previous findings that both genders can reliably identify pain in infant cries.
The researchers stated that this study is still in the preliminary stages and has raised many questions in interpreting the results and methodological aspects.
For example, participants had little to no experience in caring for infants, so these results may not necessarily reflect the physiological responses of experienced parents. Future research could uncover how different experiences affect physiological responses to NLP.
The findings of the above study were published on September 10 in the “Journal of the Royal Society Interface.”