When babies don’t like something, they cry. The reasons for this can be real pain or just dissatisfaction. However, many people do not succeed in hearing the subtle difference. As researchers find out, it takes practice.
Is the baby in pain or just whining? Surely young parents know that intuitively, don’t they? Contrary to what many assume, this ability is by no means innate, researchers report in the journal Current Biology. Being able to interpret baby cries has to be learned. According to this, only a certain group succeeds in hearing not only from well-known babies, but also from unfamiliar babies that they have never heard before, whether they are crying because of pain or are just dissatisfied.
The scientists led by Nicolas Mathevon from the University of Saint-Étienne in France included people with different levels of experience in handling babies in their analysis. This included people without any experience, parents of children of different ages, people with occasional experience such as babysitting, and non-parents with more extensive professional experience caring for young children.
For everyone there was a short training session with eight different recordings, each a few seconds long, of a single baby crying: either cries of slight discomfort when bathing at home or cries of pain when vaccinated in a pediatrician’s office. Participants were then tested on their ability to associate new crying sequences from a familiar baby with discomfort or pain from an unfamiliar baby.
Men and women with no experience of handling babies were not able to interpret the recordings correctly more often than might be expected by chance. Parents of at least five-year-old children and professionals fared better. By far the best, however, were the parents of small children under the age of two. They were often able to correctly interpret a baby’s cries even if they had never heard the infant before.
Parents of older children and people with professional experience did not do so well. That was initially surprising for the professional supervisors, said co-author Camille Fauchon, also from the University of Saint-Étienne. “But it is consistent with the notion that experienced listeners develop resistance, their sensitivity to auditory pain cues is reduced.” There were no differences between men and women in any of the groups.
According to Mathevon’s team, the results show that babies’ cries contain information that is encoded in the acoustic structure. From an evolutionary point of view, the fact that the interpretation of the cries of familiar infants can be easily learned makes sense: in humans, a network that extends beyond the nuclear family often takes care of the offspring, which also includes, for example, grandparents and more distant relatives as well as unrelated caregivers such as childcare workers.