Parents often change their speech when talking to babies, simplifying their sentences and altering the words and noises they make to sound - and this is a technical term here - "more adorable." Turns out we're not the only ones.
Baby talk, also known as motherese, is essentially a way for parents to bridge the gap between the near infinite complexities of adult speech and a newborn's complete lack of linguistic skills. A baby isn't likely to go straight to saying "water" or "bottle", so common motherese terms like "wawa" and "baba" can introduce infants to useful terms they are more likely to be able to vocalize themselves. Baby talk is also slower than normal speech, often employs a cooing intonation that the babies find soothing, and features lots of repetition. It's a seriously complex linguistic phenomenon we're talking about here.
It's not entirely verbal communication either - people's body language will often change when dealing with infants - and that opens the door for non-human versions of motherese. However, there's barely any evidence of baby talk outside humans, with the only known evidence until now being a single altered call used by rhesus macaques when dealing with their infants.
Eva Maria Luëf and Katja Liebal of the Free University of Berlin have now discovered a much more substantial example of motherese among captive lowland gorillas. They discovered that older gorillas would use a different set of gestures when initiating play with infants than they would when dealing with their peers, as New Scientist reports:
Typically, gorillas might encourage play by slapping others while making a "play face", for instance, or somersaulting, and end bouts by placing a hand on the other gorilla's head. With infants, every older gorilla used more touch-based gestures and repeated their gestures more.
Gorillas use gestures extensively in their communication, and so it's of paramount importance that infants master all the different signals, much as human infants must all become experts in spoken language. In both humans and gorillas, simplifying and repeating communication is a way to help infants pick up what they need to know faster, and the researchers say it's quite likely that we will find evidence of such behavior among all the great apes sooner or later.