Monkeys use baby talk with their infants

CHICAGO, Aug. 25 (UPI) -- Rhesus monkeys use their own type of baby talk to interact with their infants, a U.S. study found.

Research from the University of Chicago shows that female rhesus monkeys use special vocalizations to engage the attention of their infants, similar to the way human mothers use baby talk with their children.

"Motherese is a high pitched and musical form of speech, which may be biological in origin," Dario Maestripieri, a professor of Comparative Human Development, said Friday in a release. "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."

A study of rhesus macaques on an island off the coast of Puerto Rico examined vocalizations among adult females and found that grunts and girneys increased dramatically when a baby was present.

They also found that when a baby wandered away from its mother, the other females looked at the baby and vocalized, suggesting that the call was intended for the baby.