Human adults can quickly recognize a distress cry from a baby, but they can’t distinguish — at least, from the sound alone — the specific underlying message the cry is conveying, according to a study published recently in the journal PLOS ONE.
In other words, adults — and, yes, parents are included — can’t tell whether a baby’s cry is due to hunger, pain or separation anxiety.
Adults are, however, relatively good at deciphering another common type of baby vocalization: the sound the child makes when he or she is being playful.
“Our results indicate that adults almost flawlessly distinguish positive and negative infant sounds, but are rather inaccurate regarding identification of the specific needs of the infant and may normally employ other sensory channels to gain this information,” write the authors of the study.
The study was conducted in the Czech Republic and led by Jitka Lindova, an evolutionary psychologist at Charles University in Prague. Lindova and her colleagues collected recordings from the mothers of 19 babies aged 5 to 10 months old. The recordings, which were cut to 20 seconds each, captured the sounds the babies made during a range of six emotional situations: when the children were hungry, just fed, experiencing pain (while receiving a vaccination), separated from their parent or other caretaker, reunited with that parent or caretaker, and playing.
The researchers then asked 333 volunteers to listen to and assess the recordings. These participants could almost always tell when a baby was in distress (in fact, they correctly did so 98 percent of the time), but they scored very poorly at identifying the specific negative emotion involved — whether the child was hungry or in pain, for example.
The participants were also able to identify when a baby was not in distress (after being fed or reunited with a parent, or while playing) in 84 to 90 percent of the cases.
Furthermore, they could specifically distinguish the sound of a baby playing from all the other sounds 65 percent of the time — a 24 percent higher success rate than with another of the other vocalizations.
The participants who were parents did only slightly better at correctly identifying the babies’ emotions than those who were non-parents, and the scores of both men and women were statistically the same.
“Our results thus support the hypothesis that men and women are equally well predisposed to perceive and decode information from baby vocalisation,” the authors write (with British spellings.)
Caveats and implications
The study involved the sounds from only 19 babies, as well as a relatively small number of participants — all of whom lived in a the Czech Republic. It’s not clear, therefore, if these findings would pertain to people living in other countries and cultures.
Nor is it clear from the study whether the findings would be different if parents were asked to identify the meaning behind the cries and other vocalizations of their own infants.
Still, the findings are interesting, for they suggest, as Lindova and her colleagues note, that when most adults hear a baby cry, they can usually quickly determine if the child is in distress and thus needs care or protection.
Figuring out specifically what the baby is in distress about, however, takes a bit more investigation.
You can read the study in full at the PLOS ONE website.