A new research suggests that human and ape babies use similar gestures during their developmental stages
A new study conducted by the College of Staten Island, New York, found that both human and ape infants tend to use similar gestures during their developmental stages.
Babies are known to rely on gestures before they start developing language skills till they are about one year old. While human infants go on to learn words, offsprings of apes, baboons and chimpanzees progress to learn more communication signs.
According to co-author, Kristen Gillespie-Lynch, a developmental psychologist at the College, gestures are an important component in the language development stage for all infants.
In 1746, Étienne Bonnot de Condillac, a French philosopher, first proposed that language was an outcome of gestures and signs. He claimed that in the human evolutionary process, after man started walking on two legs, gestures came way before speech-enabling vocal tracts developed.
Researchers state that while apes in captivity learn some language and gestures from humans around them, infant apes in the wild don't use as many gestures as human babies. Hence, it becomes difficult to point out commonalities in language development that have biological versus environmental roots.
For the study, researchers compared an everyday video of an American baby girl and two apes that were living in the Language Research Center in Atlanta. Both apes, Panpanzee, a chimpanzee, and Panbanisha, a bonobo, received training in sign language, gesturing and vocalizations; they also went through a daily testing session.
The researchers compared the behavior of the apes through one year to 26 months to the reactions of the baby girl from 11 months to 2 years.
They found that the apes and the baby girl used more gestures than words in their initial months and those gestures were similar. The baby girl and the two apes reached out with hands if they wanted something and lifted their arms when they wanted to be carried.
With time, both the species started developing vocal skills for communication. However, researchers noticed that the baby girl's transition to using words was more dramatic than the apes' transition to using sign language and vocalizations. They noticed that the baby girl communicated more to share her experiences, while the apes only used gestures as a way to get something.
As gestures play an early role in communication in all babies, it probably must have played a similar role in a common ancestor, Gillespie-Lynch noted.
