Along with Dr. Paul Ekman's benchmarking work that proved the universality of facial expressions of basic emotions, prevailing behavioral researches in world of psychology are attributed to human nonverbal communication. The strength of the contributions made by of Dr. Ekman left no room for doubt and today no one questions that basic emotions have a universal facial expression pattern that is contained in our genetic makeup.
But what about the gestures we make by hands or head? Are they learned or genetically inherited? Let's find out what a research says.
My approach in this article is taking you attention to a research conducted by scientists at the Max Planck Institute for Evolutionary Anthropology in Leipzig (Germany) that has recently been published by BBC Science.
|Group of wild bonobos - Closest primate cousins to humans|
According to scientists and as they managed to film on many occasions, several members of primate species called as Bonbons shook their heads from side to side to prevent others to do something they didn’t want. In one of the recordings, a mother shook her head to stop her baby playing with food.
Researchers say that this could be a precursor to the behavior of shaking head used by humans observed in one of our closest primate relatives. Chimpanzees seem to shake their heads to avoid behaviors that do not satisfy.
"Our observations are the first to report the use of negative movement of head in bonobos," says Christel Schneider, who led the study. According to his research, the recorded videos in Leipzig Zoo, a chimp mother shook her head in disapproval of playing with food by her baby.
"Ulindi is trying to prevent her daughter, Luiza, keep playing with a piece of leek", explains the researcher. "As Luiza ignored, despite repeated attempts to stop her, Ulindi finally shook his head at the young," he adds.
"No" from Bonbons
It is known that African great apes such as Bonobos (Pan paniscus) and Chimpanzees (Pan troglodytes), nodding used as negative (tilt or shake) to communicate with other members.
It was already known that bonobos use head shaking to initiate interactions with other members of their group and start playing. However, this is the first study that shows in films that an ape shaking his head in a negative context, to avoid or prevent other bonobo’s behavior.
Scientists based in Germany observed this behavior when the animals were being analyzed as part of a larger study about communication of offspring of the great apes.
With video cameras recorded the gestures and behavior of bonobos, chimpanzees, gorillas and orangutans in six European zoos. During the investigation, they found four bonobos shaking their heads in this way on 13 different occasions. Previously there were only anecdotal reports of chimpanzees shaking his head to indicate "no."
Scientists believe that the negative head movement is a precursor of the same behavior in humans. Scientists explain that bonobos use a wider range of head gestures than chimpanzees and are considered to be more sophisticated to use their head to indicate any meaning.
The authors say that these sophisticated systems of communication might have arisen because of apparently sophisticated society, tolerant, cooperative and democratic living in these animals where complex social structures and hierarchies diffuse. So perhaps bonbons developed the head nod to say "no" and negotiate conflict situations.
However, researchers are cautious and say they cannot be sure that the animals really want to deny when they shake their heads in this way. But so far this is still the best explanation, they say.
And as he told the BBC Schneider, we must clarify that the head movement is not always associated with something negative. In many countries moving head side to side is symbol of approval too.
[This article is translation of original article "Gestos, ¿aprendidos o genéticos?" written in Spanish (Español) by my friend, associate, and nonverbal communication researcher - Prof. Dr. Rafael López Pérez from Universidad Camilo José Cela, Madrid (Spain).]