Man has been described as a social animal. From the beginning of our lives we strive to be accepted in a particular society or a particular group. However, it is considered normal to have many friends at a young age. The more friends one has, the more the person is considered active and social. But as we grow older, we become wiser. We learn a lot of important things, one of which is that not everyone is truly your friend and such people are not worth it. Older people tend to limit themselves to those whom they feel comfortable with. They also tend to be less interested in relationships that cause conflicts.
A recent study by a group of psychologists and primatologists from the Harvard Department of Human Evolutionary Biology has suggested that this type of social behaviour also exists in chimpanzees, one of our closest living relatives.
The study, made between 1995 and 2016, was to observe social behaviour of male chimpanzees at the Kibale National Park in Uganda. Only male chimpanzees were observed because they have a stronger social bond than the females.
Chimpanzees form large multi-male and –female social groups. Similar to human society, it consists of a definite social hierarchy. The dominant male is as the alpha male. It is not necessary for the alpha male to be the biggest or strongest but he has to be the most intelligent that can influence the other members of the group.
Studying the male groups, the researchers found that the older chimpanzees spent more time and grooming those with whom they have mutual relationship. Older chimpanzees can also spend more time with their aging friends and are known to be more peaceful. This preference is known as positive bias.
“The really cool thing is that we found that chimpanzees are showing patterns that mirror those of humans,” said Alexandra Rosati ’05, an assistant professor of psychology and anthropology at the University of Michigan and one of the paper’s lead authors.
This social behaviour had been depicted in the film Rise of the Planet of the Apes (2011). In the film, a chimpanzee named Caesar who after being exposed to a drug for curing Alzheimer’s disease, begins to show higher intelligence than the normal chimpanzees. Some years later, when Caesar is taken an animal control centre, he is bullied by the other chimpanzees. However, after showing his increasing intelligence, Caesar claims the position of alpha and helps the other chimpanzees to escape.
Due to a research by Mary-Claire King in 1973, it was found that there’s over 90% similarity between the DNA of human beings and chimpanzees. Therefore, the result of the study wasn’t surprising to the scientists.
“It raises the possibility that we are seeing behavioural systems that have been shared evolutionarily back to our common ancestor, around seven or eight million years ago,” said Richard W. Wranham, Professor of Biological Anthropology and founder and co-director of the Kibale Chimpanzee Project.