A new study shows that not only humans but also monkeys are subject to negative influence and pressure from their peers!
A nine-year study of vervet monkeys (Chlorocebus pygerythrus) has demonstrated that social traditions are transmitted across different groups of animals. Scientists from the University of Lausanne in Switzerland and Paul Sabatier University in France claim that monkeys experience a phenomenon similar to peer pressure in humans.
This leads to males joining more sociable groups quickly adapting to the social communication styles of their new companions.
Bad Company
Researchers observed nearly 250 monkeys in South Africa over nine years, analyzing data from more than 84,000 social interactions.
The vervets inhabited three different communities (Ankhas (AK), Baye Danki (BD), and Noha (NH)), which significantly differed in the level of sociability among the animals in each group.
Observations showed that members of the AK group groomed each other more frequently—when one monkey groomed another, it usually received a reciprocal action.
Elena Kerjan, the lead author of the study, noted: “We found that individuals in the AK group exhibited significantly more affiliative behavior compared to the other two groups, and this difference remained stable throughout the 9 years of the study.”
Kerjan compares this to “the exchange of grooming between individuals.”
“If you are groomed 100 times a year, and you have only done it twice, your friend might consider your relationship to be completely unfair. These are the kinds of disparities we observed between our groups,” explains Elena Kerjan, the lead author of the study.
Remarkably, males transitioning from one group to another quickly adopted the social styles of their new environment. The scientists noted that social pressure worked both ways: males leaving the AK group soon became less active in grooming each other.
Social Norms
Primates, including vervets, have highly developed social systems and are capable of maintaining long-lasting and complex relationships with other members of their species.
Charlotte Canteloup, a co-author of the study, stated: “All vervets are social animals, and they use various types of behavior to establish and maintain social bonds. Our hypothesis is that males adjust to the social norms of their new group by mimicking the behavior of their new peers. In other words, they adopt the social fashion of their new environment.”
This may be related to unconscious mimicry or pressure from other monkeys. In any case, they are definitely influenced by their surroundings.
