Researchers conducted a study to figure out how spoken language evolved in humans. They analyzed hours of video of a female chimp, a female bonobo and a little girl. The researchers found that they all used gestures to communicate.

The study was published in Frontiers in Psychology this week, in which the researchers noted that skeletons can be fossilized, but language cannot.

To figure out the evolution of spoken language, they observed similarities between the three closely related species to understand the ways that our ancestors would have used to communicate more than five million years ago.

The findings revealed that a similarity of gestures among bonobo, chimpanzee and child was established at comparable periods of development.

The gestures were communicative for all the three species, because they were paired with eye contact, a vocalization or persistence. The child was far more likely to combine her gestures with some kind of vocalization. Eventually with age, the child was more likely to have those vocalizations converted into words.

"It's a new kind of evidence in favor of the gestural origins of language, and it's also a new kind of evidence in favor of the co-evolution of gesture and speech", said one of the study's authors, Patricia Greenfield, a psychology professor at the University of California at Los Angeles.