Aug. 24, 2007 — A person who excitedly approaches infants and speaks to them in a high-pitched, musical voice has a behavior in common with female monkeys, suggests a new study, which found that female rhesus macaques use "baby talk" when they see another monkey's offspring.
Since "baby talk," also known as "motherese," may be an evolved trait in certain primates, the finding indicates this gentle way of vocalizing could play a key role in promoting positive relationships between parents and babies, as well as between adults and other grown-ups.
"Baby talk" used by the macaques has a soft, nasal sound. It is mostly prompted by the fact that "all monkey females are interested in babies," co-author Dario Maestripieri told Discovery News.
He and colleagues Jessica Whitham and Melissa Gerald documented the sweet-sounding macaque vocalizations — called "grunts" and "girneys" — along with associated behaviors of free-ranging monkeys on the island of Cayo Santiago near the southeastern coast of Puerto Rico.
The study is published in the current issue of the journal Ethology.
Two species of ape use human-like gestures to communicate to each other. Kasey-Dee Gardner reports.
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While the researchers determined both male and female monkeys have the ability to produce the sounds, they noticed males rarely used them.
Females, on the other hand, nearly always only emitted the sounds when they encountered another female's baby, such as when an infant would wander away from its mother.
