Data from: Male monkeys use punishment and coercion to de-escalate costly intergroup fights

In numerous social species, males direct aggression towards female group
members during intergroup fights, and this behaviour is commonly thought
to function as mate guarding, even though males often target non-receptive
females. In studying intergroup fights in a wild population of vervet
monkeys, we found that male intragroup aggression was primarily directed
towards individuals who had either just finished exhibiting, or were
currently attempting to instigate intergroup aggression. Targeted females
were less likely to instigate intergroup aggression in the future,
indicating that male intragroup aggression functioned as coercion (when
directed towards those who were currently trying to instigate a fight) and
punishment (when directed towards those who had recently fought). These
manipulative tactics effectively prevented intergroup encounters from
escalating into fights and often de-escalated ongoing conflicts. Males who
were likely sires were those most likely to use punishment/coercion,
particularly when they were wounded, and therefore less able to protect
vulnerable offspring should a risky intergroup fight erupt. This work,
along with our previous finding that females use punishment and rewards to
recruit males into participating in intergroup fights, highlights the
inherent conflict of interest that exists between the sexes, as well as
the role that social incentives can play in resolving this conflict.
Furthermore, unlike other studies which have found punishment to be used
asymmetrically between partners, these works represent a novel example of
reciprocal punishment in a non-human animal.