Monkey mothers use “baby talk” too
Monkey mothers use “baby talk” too
mongabay.com
August 24, 2007
Female rhesus monkeys use special vocalizations to communicate with infants much like human mothers use “baby talk” or “motherese” reports a new study by researchers at the University of Chicago.
“Motherese is a high pitched and musical form of speech, which may be biological in origin,” said Dario Maestripieri, an associate professor in Comparative Human Development at the University and lead author of the study published in journal Ethology. “The acoustic structure of particular monkey vocalizations called girneys may be adaptively designed to attract young infants and engage their attention, similar to how the acoustic structure of human motherese, or baby talk, allows adults to visually or socially engage with infants.”
The researchers studied a group of free-ranging rhesus macaques, which live on, but are not native to, an island off the coast of Puerto Rico.
Rhesus macaque monkeys. Image courtesy of the University of Chicago. |
They found that “grunts” and “girneys” exchanged between adult females increased dramatically when an infant was present. When a baby wandered away from its mother, the other females looked at the baby and made the ‘baby talk’ noises to draw it back.
“Adult females become highly aroused while observing the infants of other group members,” explains lead author of the article, Jessica Whitham, a recent Ph.D. graduate of the University of Chicago, who investigated this topic as a doctoral student at the University and currently works at Brookfield Zoo near Chicago. “While intently watching infants, females excitedly wag their tails and emit long strings of grunts and girneys.”
“The calls appear to be used to elicit infants’ attention and encourage their behavior,” the researchers conclude.
Maestripieri say that the rhesus grunts and girneys “fall into the category of vocalizations not intended to convey specific information, and appear to be used to attract other individuals’ attention or change their emotional states,” according to a statement from the University of Chicago. “When females vocalize to young infants, however, the infants’ mothers infer that the females simply want to play with the infants and are unlikely to harm them. Therefore, these vocalizations may facilitate adult females’ interactions not only with infants, but with the infants’ mothers as well.”
This article is based on a news release from the University of Chicago.