Bigger brains help social primates to make up after a fight, study says

Bigger brains help social primates to make up after a fight, says Manchester study
Credit: University of Manchester

Social primates with bigger brains are likely to use their added cerebral power to cope with conflict, a study from The University of Manchester has revealed.

The surprise findings suggest that social skills, which are very sophisticated in , help individuals cope with aggression and competition caused by living in large groups.

The Manchester study was led by Veronica Cowl, a PhD student based in Manchester's School of Earth and Environmental Sciences, with colleague and senior author Dr Susanne Shultz. The research has been published in the journal Behavioral Ecology.

Cowl looked at the associations between group size, and behaviours that are recognised as 'prosocial' and 'cooperative' (eg working together as a group on a collective action) and their relationship to aggressive behaviours that led to incidents of , termed as agonism.

The Manchester study reviewed previous publications on 45 different wild populations of primates across 23 species.

The three species with very high levels of agonism are chacma baboons (Papio ursinus; up to 2.9 events per hour); capuchins (Cebus capuchinus; up to 1.43 agonistic events per hour); and a population of black and white ruffed lemurs (Varecia variegata variegata; up to 1.4 events per hour).

The species with the lowest rates of agonism were brown lemurs (Eulemur fulvus fulvus; 0.03 events per hour) and black howler monkeys (Alouatta pigra; 0.01 events per hour).

The original studies examined how variation primate agonism related to ecological variables, such as risks from predators or food competition.

However, the Manchester team was interested in explaining why there is strong association between brain size and group size in primates.

"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," explained Veronica Cowl.

"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).

Although group-level agonism increases with , dyadic agonism decreases. (Dyadic agonism identifies how much agonism each individual animal directs towards each other individuals within the group).

Ms Cowl added that this suggests that either individuals in larger groups can buffer aggression better or that only species with low levels of dyadic conflict can maintain large groups and stable .

"It seems large-brained primates have evolved to cope with the challenges of conflict and coordination inherent in living in ," added Dr Shultz.


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More information: Veronica B. Cowl et al. Large brains and groups associated with high rates of agonism in primates, Behavioral Ecology (2017). DOI: 10.1093/beheco/arx041
Journal information: Behavioral Ecology

Citation: Bigger brains help social primates to make up after a fight, study says (2017, March 27) retrieved 15 June 2019 from https://phys.org/news/2017-03-bigger-brains-social-primates.html
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Mar 27, 2017
More evidence that tribalism has created the human species. The tribes that prevailed in conflict were better at maintaining internal cooperation and amity in conjunction with external emnity (the tribal dynamic).

Group selection also selected for larger brains.

They still cant use the word tribe, notice that? Too many uncomfortable connotations.

Mar 27, 2017
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
-The advent of technology caused chronic overpopulation among humans. This exacerbated intratribal as well as intertribal competition, and accelerated the development of our species.

Mar 27, 2017
This throws a bright light on why some simple folk get fixations on others, unable to change or outgrow it.

Mar 27, 2017
@STOLEN VALOR LIAR-kam
no
- per the study
Moreover, we find a distinct absence of relationships between agonism and the prevalence of prosocial, cooperative behaviors. That overall rates of agonism increase but dyadic rates decrease with group size suggests that individuals in larger groups either can buffer aggression better or only species with low levels of dyadic conflict can maintain large groups
one of the methods used by our large brains to mitigate agonism is cooperative behaviours - so when you come to a science site and want to post, the behaviour states you should present valid verifiable information to argue a point

when said point is false and proven as such, then you should redact it or post a clarification/addendum

one who posts lies, pseudoscience, or religion that are proven to be such, like yourself, are the pseudonymous fixated sniping trolls disrupting commentary without validation

per your own request, then...

Mar 27, 2017
Okay, . . it's your fixation, not mine.

Mar 27, 2017
Anything that competes to exist is under pressure to evolve. If primates evolve to perform better in groups, then groups with such primates have a competitive advantage and have effectively evolved. Once you accept that groups evolve, a variety of otherwise difficult to explain behavior begins to make sense.

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