Amaya Palama and collaborators have discovered that as early as 6 months babies are able to associate facial expressions with voices that express those emotions.
As every newly parent knows, babies cry to express their emotions and needs (hunger, sleep, diaper change).
But the question that Palama asked herself is: “Can babies undertand people’s emotions?”
24 six-month-olds listened for 20 seconds to a voice expressing happiness, anger, or no particular emotion. Subsequently, they observed two faces for 10 seconds, one expressing happiness, the other anger. The scientists followed the children’s eyes movements to calculate the amount of time it took to observe each face and to check whether they observed a specific part of the face for a shorter or longer amount of time after listening to a particular tone of voice.
The results suggest that after listening to the happy voice, babies paused longer to observe the angry face, and especially the mouth of the angry face.
This peculiar behaviour suggests that 6-month-old babies are able to transfer auditory information relating to happiness to the visual channel and therefore to identify the emotion of happiness not only at the auditory level, but also at the level of facial expressions.
Palama et al., “Are 6-month-old human infants able to transfer emotional information (happy or angry) from voices to faces? An eye-tracking study”, (2018), https://doi.org/10.1371/journal.pone.0194579