Why don't we just kiss and make up?
LOOK at the world's worst trouble spots and you can't fail to
notice they have one thing in common: tit-for-tat attacks between warring
parties. Escalation of violence is incredibly destructive, yet we humans
find it very difficult to break the vicious cycle. It seems we are not good
at conflict resolution. Perhaps we could learn a lesson or two from the
spotted hyena.
07 May 2005
New Scientist Print Edition.
Lee Dugatkin
Spotted hyenas are highly sociable. Like other animals that live in
close-knit groups, they don't always get along. But spotted hyenas don't
hold a grudge. Within about 5 minutes of a fight, the erstwhile combatants
can often be seen playing, licking or rubbing one another, or engaging in
other friendly acts to dissipate the tension. And they are not the only
animals with a penchant for kissing and making up. In their book Natural
Conflict Resolution, Filippo Aureli from Liverpool John Moores University,
UK, and Frans de Waal from the Yerkes Primate Center at Emory University,
Atlanta, Georgia, document reconciliation in no less than 27 species of
primates. Bottlenose dolphins also do it. Even goats. So why can't we be
more forgiving?
Admittedly, human interactions are far more complex. But perhaps we can draw
some lessons from the study of conflict resolution in nature. Not only have
ethologists discovered that it is a lot more common than you might expect,
they are also working out the costs and benefits of conflict resolution.
Their ideas about when, where and how reconciliation works in nature could
help us to improve the chances of settling our own disputes.
When it comes to making up, our primate cousins get top marks. De Waal
describes a typical incident in which Hennie, a young female chimp, has been
slapped during a passing charge by Nikkie, the leader of the group. Hennie
retires from the fray, at first caressing the spot where she was hit and
then just lying in the grass and staring into the distance. "More than 15
minutes later Hennie slowly gets up and walks straight to a group that
includes Nikkie," de Waal writes. "Hennie approaches Nikkie, greeting him
with a series of soft pant grunts. Then she stretches out her arm to offer
Nikkie the back of her hand for a kiss. Nikkie's hand kiss consists of
taking Hennie's whole hand rather unceremoniously into his mouth. This
contact is followed by a mouth-to-mouth kiss."
Note, it is Hennie, the chimp who came off worst in the argument, who
instigates the reconciliation. In fact, this is a general pattern for most
instances of conflict resolution. Gabriele Schino from the National Research
Council in Rome, Italy, even found it in goats. After she had induced
conflict over food, she found that 16 per cent of all interactions between
goats were reconciliatory, consisting of friendly acts such as grooming and
muzzle rubbing between animals that had been fighting previously. As in
primates, this was most often initiated by the loser of the fight.
Like hyenas and most primates, goats are sociable animals. And this seems to
be one of the key attributes of species that go out of their way to resolve
their conflicts. Hardly surprising then, that such behaviour is also found
in dolphins. Although they seem to have happy grins perpetually plastered on
their faces, dolphins are surprisingly aggressive. And, sure enough, they
are big on conflict resolution, as Amy Samuels from Woods Hole Oceanographic
Institute, Massachusetts, and Cindy Flaherty from Brookfield Zoo in Chicago,
Illinois, have observed. While studying a small group of bottlenose dolphins
at the zoo, Samuels and Flaherty noticed that after a fight opponents often
engaged in "gentle rubbing" or "contact swims", in which one dolphin towed
another through the water.
Stress-busting
Documenting such interactions has made ethologists aware of just how common
conflict resolution is in nature and they are developing theories about how
conflict-resolving behaviour evolves. Their cost-benefit models attempt to
make specific predictions about when and where potential combatants will
devise non-aggressive ways to resolve disputes, and under what circumstances
they will adopt special conciliatory behaviour to minimise the chances of
further conflict after an altercation. These models are now being put to the
test.
The benefits of being in a social group often depend on its stability. That
means conflict resolution is likely to figure large in groups where
aggression will really rock the boat - if the size of a group is important
for its successful functioning, for example. If subordinate individuals were
to defect every time they lost a fight, the group would be in a constant
state of flux, with potentially disastrous results, in terms of less food,
fewer individuals available to fight competing groups, and so on. Even if
subordinates stayed put, without reconciliation they would probably have
limited access to resources. Those who try to resolve conflicts can avoid
this fate. That gives them an advantage over others who do not engage in
this behaviour, and explains how it might have evolved.
But it takes two to kiss and make up. Why would the winner of a fight play
ball? Because dominant individuals also have something to gain from
reconciliation, it turns out. Without resolution, they can never be sure a
fight won't flare up again. And that can lead to anxiety and raised levels
of stress hormones called corticosteroids. These in turn compromise the
immune system making individuals more likely to succumb to infection.
Evidence of reconciliation's value as a stress-buster comes from
physiological measurements taken before and after it occurs, showing that
making up leads to a decreased heart rate.
Given these biological and psychological costs, it is not surprising that
natural conflict resolution is rife in tightly knit social groups. In fact,
reconciliation is so beneficial to a group of chimps that if neither of the
warring individuals will initiate it, a third party may step in to broker a
deal. Nevertheless, not all cases of aggression are equally likely to
involve resolution, because the costs and benefits of reconciliation vary
depending upon what caused the incident in the first place. Researchers have
found, for example, that in primates at least, reconciliation almost never
happens when individuals fight over food, whereas it is common following
aggression that appears to have no specific motive. In general, fights over
a finite resource tend to have a natural lifetime that ends when the
resource is used up. Resolution is unnecessary because such fights are
unlikely to affect long-term bonding between group members. Fights that are
more nebulous in origin, by contrast, have the potential to flare up again
unless there is closure.
Feuding families
In addition, some pairs of combatants are more likely to seek reconciliation
after a fight than others. One of the most influential models of natural
conflict resolution is the valuable friendship model, suggested by de Waal
and Aureli, which is built on the idea that the more you depend on another
individual, the more costly it is to allow a rift to develop. Detailed
controlled experiments testing the hypothesis are rare, but one study with
long-tailed macaques found that reconciliation is indeed more likely after
fights between partners who normally help each other get food than between
other individuals. What's more, for a wide range of primates the most
valuable social relationships tend to be among kin, and disputes within
families often end in reconciliation. This is not the case with spotted
hyenas, however. Kay Holecamp from Michigan State University and her team
have found that hyenas are more likely to initiate reconciliation with
non-kin than with kin. Not, they suggest, because family relationships are
less valuable, but because kin may be more forgiving of one another than
strangers are.
These are the benefits of reconciliation, but what of the costs? There must
be some or you would expect to find conflict-resolving behaviours in all
animals that live in groups and in all contexts. One possibility is that
reconciliation requires a level of cognitive complexity beyond the reach of
many species. The evidence, however, does not support this. Behaviours that
are cognitively sophisticated tend to involve learning. But young animals
are just as competent at reconciliation as adults. So if cognitive
constraints do not seem to be the problem, what is?
An obvious answer is that when former aggressors come together to try to
make up, fighting may re-ignite. One way around this problem is to adopt
special reconciliation rituals that are hard to misinterpret. Indeed
comparative studies reveal that in species where reconciliation is most
common it is more likely to be associated with unique, unambiguous actions
such as "embracing" in pig-tailed macaques and "grasping" in Tonkean
macaques. But even this cannot get around the fact that the benefits of
reconciliation may outweigh the costs for only one member of a warring pair.
Finally, reconciliation may be unnecessary in certain societies. Ring-tailed
lemurs, for example, are either friends, almost always interacting
peacefully and to mutual benefit, or enemies who never get along. Between
friends, reconciliation is unnecessary. Between enemies it is simply a waste
of time.
As our understanding of natural conflict resolution grows, it is tempting to
hope that we can apply what we have learned to improve human relations. The
cost-benefit approach certainly looks like a step in the right direction,
but we will need much more detailed work on non-humans before we can develop
general predictions that might apply to us. The possibilities are
tantalising, though.
Take the study of rhesus and stumptail monkeys done by de Waal and colleague
Denise Johanowicz over a decade ago. Rhesus monkeys are aggressive and
rarely opt for reconciliation; stumptails on the other hand have a talent
for making up. The researchers wanted to see what would happen if they
reared juveniles of the two species together. They found that the young
stumptails exerted a benign influence over the slightly younger rhesus
monkeys, whose behaviour towards other group members gradually became more
and more conciliatory. The idea that natural conflict resolution can be
taught by observation means that there is some hope for Homo sapiens.
The different reconciliation styles of chimpanzees and bonobos could also
offer a pointer to human behaviour. Bonobo society is particularly
harmonious, and one way they achieve this is through reconciliation. This is
a notoriously sexy affair, often involving "mounts" and other erotic
activities. In contrast, sex is far less important in chimp conflict
resolution. But, according to de Waal, what really makes the difference is
not the sexual element but who instigates reconciliation. Chimps follow the
usual pattern, with the loser trying to make amends. For bonobos, however,
it is the winner, the individual wielding the power, who makes the first
move. Now there is a lesson for us all.
Lee Dugatkin is a behavioural ecologist at the University of
Louisville, Kentucky. His latest book Principles of Animal Behavior is
published by W. W. Norton (2004)
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