Male vervet monkeys attack members of their own group to prevent them from escalating intergroup encounters into high-risk fights, or to de-escalate ongoing intergroup fights. In contrast, female monkeys use “the carrot and the stick” to promote male participation in intergroup fights, anthropologists at the University of Zurich and University of Neuchâtel have shown.
Social species engage in a number of cooperative activities including hunting, raising offspring, defending the group against predators, and fighting with neighboring groups. However, since social groups are collections of unique individuals, each member of the group obtains different benefits and experiences different costs when engaging in these cooperative activities.
As a result, group members may often disagree on when to cooperate, and when to defect. This is particularly true when it comes to intergroup fights, as participation carries a serious risk of injury or death, but winning can determine whether the group has access to important resources.
Punishment and coercion
While we know a great deal about how humans resolve such conflicts of interests, we know relatively little about the various mechanisms employed by other social species. A new study carried out by researchers of the University of Zurich shows that male vervet monkeys use punishment and coercion to de-escalate costly intergroup fights.
In particular, this strategy was used by males who were likely to have sired infants in the group, but were themselves wounded and so may have felt unable to defend their offspring should the need arise.
Aggressive behavior against combative group members
While conducting her doctoral research at the Inkawu Vervet Project in South Africa, Jean Arseneau-Robar, the first author of the study, observed males attacking their own group members during intergroup fights. “It has always been assumed that males exhibiting this behavior want to prevent females from mating with males in the opposing group. These acts of male aggression have thus always been interpreted as acts of mate defense,” says anthropologist Jean Arseneau-Robar.
However, the researchers noticed that male vervets usually did not attack female group members who were trying to affiliate or mate with males from the opposing group. Instead, males were more likely to direct aggression towards group members who were either trying to instigate a fight, or who had recently fought.
Females use "the carrot and the stick"
Erik Willems, who led the research, says: “We have recently shown that females in this species use both aggression as punishment and grooming as reward to manipulate the participation of male group members during intergroup fights.”
The researchers now wanted to know if males might similarly be trying to influence the outcome of intergroup fights. Indeed, they found that when males used aggressive behavior against their own group members, it effectively manipulated the behavior of their targets. However, male punishment and coercion inhibited group members from fighting, de-escalating the entire intergroup conflict.
De-escalation through punishment
UZH professor Carel van Schaik adds: “It was really interesting to see that while females use punishment and rewards to try and rally the troops, males actually use punishment and coercion to try and stifle the fighting, effectively keeping things calm and safe for small, vulnerable infants.”
Redouan Bshary, professor at the University of Neuchâtel, notes: “Usually, it’s the larger or more powerful individuals that punish the weaker ones. Our findings in the vervet monkeys are novel because here, both females and males are equally able to use this manipulative strategy. Importantly, females often form a coalition when punishing males, using strength in numbers to compensate for their smaller size.”
Arseneau-Robar TJM, Müller E, Taucher AL, van Schaik CP, Bshary R und Willems EP. 2018. Male monkeys use punishment and coercion to de-escalate costly intergroup fights. Proceedings of the Royal Society B: Biological Sciences 20172323. DOI: 10.1098/rspb.2017.2323
Jean Arseneau-Robar, PhD / Erik Willems, PhD
Department of Anthropology
University of Zurich
Phone +41 44 635 54 01
E-mail: firstname.lastname@example.org / email@example.com
Rita Ziegler | Universität Zürich
Discovery of genes involved in the biosynthesis of antidepressant
09.12.2019 | Leibniz Institute of Plant Genetics and Crop Plant Research
Scientists have spotted new compounds with herbicidal potential from sea fungus
09.12.2019 | Far Eastern Federal University
Using a clever technique that causes unruly crystals of iron selenide to snap into alignment, Rice University physicists have drawn a detailed map that reveals...
University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making
In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...
With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction
The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...
Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.
Fibroblasts kit - ready to heal wounds
Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.
In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
09.12.2019 | Earth Sciences
09.12.2019 | Information Technology
09.12.2019 | Life Sciences