Emotional response triggered by distress in babies' cries, study finds

The cry of a distressed baby triggers a rapid emotional response in both men and women that is enough to make them physically hotter, researchers say.

- Ian Sample

Thermal imaging revealed that people experienced a rush of blood to the face that raised the temperature of their skin when they were played recordings of babies wailing.

The effect was stronger and more synchronized when the babies were more distressed, leading them to produce more chaotic and disharmonious cries. The work suggests that humans respond automatically to specific features in cries that ramp up when babies are in pain.

"The emotional response to cries depends on their 'acoustic roughness'," said Prof Nicolas Mathevon at the University of Saint-Étienne in France. "We are emotionally sensitive to the acoustic parameters that encode the level of pain in a baby's cry."

When a baby is in real distress, they forcefully contract their rib cage, producing higher-pressure air that causes chaotic vibrations in the vocal cords. This produces "acoustic roughness", or more technically, disharmonious sounds called nonlinear phenomena (NLP).