LONDON, March 28 (PNA/Xinhua) — Bigger brains help social primates to make up after a fight, research at the University of Manchester revealed Monday.
Social primates with bigger brains are likely to use their added cerebral power to cope with conflict, the study showed.
The university said the surprise findings suggest that social skills, which are very sophisticated in primates, help individuals cope with aggression and competition caused by living in large groups.
The study, published in the journal Behavioral Ecology, was led in Manchester by Veronica Cowl, a PhD student based in the university’s School of Earth and Environmental Sciences.
Cowl looked at the associations between group size, brain size and behaviours that are recognised as “prosocial” and “cooperative”, such as working together as a group on a collective action, and their relationship to aggressive behaviours that led to incidents of conflict termed as agonism.
The three species with very high levels of agonism are chacma baboons, capuchins and a population of black and white ruffed lemurs.
The species with the lowest rates of agonism were brown lemurs and black howler monkeys.
Earlier studies examined how variation primate agonism related to ecological variables, such as risks from predators or food competition.
The Manchester team was interested in explaining why there is a strong association between brain size and group size in primates.
Cowl said: “Our research indicates that the increase in brain size is likely to be a consequence of high levels of competition in large groups. It seems that large-brained primates have had to develop strategies to cope with high rates of conflict.”
“This is of particular importance as primates are noted for their social cognition — for example, they are able to understand social relationships between individuals, track social relationships and can develop social strategies.”
The Manchester researchers also saw different patterns between the overall level of agonism in a group and the amount of conflict between any two individuals within the group.
Cowl added that this suggests that individuals in larger groups can buffer aggression better or that only species with low levels of dyadic conflict can maintain large groups and stable social relationships.
Dr Susanne Shultz, the senior author on the paper, said: “Now we have shown that big brains, big groups and conflict are related to each other, this helps to answer an enduring puzzle about why primates in larger groups have larger brains.
“It seems large-brained primates have evolved to cope with the challenges of conflict and coordination inherent in living in large groups.”