A Brief Overview of Da Waal’s Political Book: Chimpanzee Politics

Introduction: The Arnhem chimp colony had about 25 individuals housed in an outdoor enclosure of almost two acres. Partially wooded, the enclosure has a mixture of live trees protected by electrical fencing and dead ones.

Over a hundred recurring gestures and recurring signals have been observed in Arnhem, all of which have also been seen in the wild.

One of the phenomena that makes aggression, social behavior, and communication difficult to observe in chimps (other than the sheer speed with which things happen) is side-directed behavior. Two chimpanzees in an encounter (aggressive or otherwise) will either initiate or be on the receiving end of interactions from other chimpanzees. They will recruit support, have their weapons confiscated by females, etc.

Chimps are fairly aggressive animals; nevertheless, reconciliations are an important aspect of social life. After conflict, reconciliation almost always takes place, involving kissing, mutual grooming, etc. This may be mediated by a third party (usually a female in the case of male-male conflict).

Coalitions occur routinely. They are one of the main reasons that brute strength is seldom the only, or even leading, determinant of who becomes alpha male.

Though it has been common in animal behavior circles to avoid attributing thought, rationality, and so forth to animals, this is often unavoidable when looking at chimps; their behavior is highly strategic.

Chapter 1: Chimpanzee personalities: Prior to the introduction of the males, the dominant chimp in the colony is an elderly female named Mama. Her trusty sidekick is another female named Gorilla. Gorilla is a loyal ally, and therefore has high status among the females. She is very fond of children, and was the first chimp ever to be trained to bottle feed a baby chimp (Roosje).

Two males, Yeroen and Luit, new each other prior to coming to Arnhem, and may have been called friends. Yeroen usually strike observers as a crafty, calculating fellow, whereas Luit seems more open-hearted and sympathetic. Nikkie was introduced later to the colony, and became an adult while there, in about 1976. Dandy was even younger, and was never generally accepted by the other males.

Chapter 2: Two power takeovers: From 1974 to 1976, Yeroen was the unchallenged alpha male of the colony. To outside observers, it looked like this rested on unparalleled physical strength. He appeared to be bigger than the other males, largely because his hair was always slightly on end. Other males (and females) would engage in a behavior called submissive greeting. The greeter would bow down and emit a series of “pant grunts.” De Waal distinguishes between real dominance (the sum total of aggressive encounters) and formal dominance (who greets whom). These are often correlated, but need not be identical.

Luit first challenges Yeroen by circling him six or seven times. The apparent size disadvantage has vanished. About an hour later, he runs over and slaps Yeroen, who does not retaliate immediately, but instead goes over to a group of females and embraces each in turn. Together, the whole gang chases him away.

The next phase of Luit’s campaign was to socially isolate Yeroen from the females. He would punish females who associate with him. Of course, Yeroen and a female together could have overcome Luit, but another factor entered the equation: Nikkie formed an open coalition with Luit. He seldom intervened directly when Luit was in trouble, but he used the chaos to engage in his own campaign to get some respect from the females. He would even grab them and throw them. Sometimes they would gang up on him and chase him, but he was so acrobatic that he always managed to get away. Meanwhile, Luit was soliciting support from the females, by being extremely nice to them except on those occasions when he punished them for associating with Yeroen.

After a couple of months, it was clear that Yeroen was losing. He started throwing temper tantrums when the females would not support him in his fights with Luit, which was more and more often due to the combined influence of Luit and Nikkie.

The whole power takeover took about six months, during which there were only five serious fights between the males. The last one was clearly won by Luit. It is not the case that Luit took over the alpha male position because he won the last fight; rather, he won the last fight because his self-confidence was up because he was winning the overall dominance struggle.

The dominance struggle was over when Yeroen “greeted” Luit for the first time. There was widespread joy in the chimp colony; Everyone knew this meant peace. When this happened, Yeroen slipped all the way to third place in the hierarchy, behind Nikkie as well as Luit.

One most not get the impression that all the time was spent fighting or even displaying. In fact, the males engaged in conflict spent an elevated amount of time grooming each other during this period.

As leader, Luit adopted a brand new policy: that of peacemaker. When two chimps started fighting, he would force them apart without taking sides. When he had to take sides, he would take the part of the weaker chimp in an increasing majority of cases, just as Yeroen had done as alpha male. Presumably, this was a way of insuring support.

Gradually after this a coalition formed between Yeroen and Nikkie. Yeroen would on occasion refuse to greet Luit, and even attack him, and sometimes get Nikkie’s support. Such encounters would end with Luit thoroughly scared and Yeroen “greeting” Nikkie, exactly what he had refused to do to Luit.

Gradually, this led to displays of defiance by Nikkie toward Luit. Yeroen would show solidarity by mounting Nikkie. Once it was clear that this was a challenge to Luit’s leadership, tension mounted rapidly. Again, this was also marked by extensive grooming between Luit and Nikkie. Eventually, the tension culminated in a fight, where Yeroen and Nikkie chased Luit up a tree and attacked him. Several females came to Luit’s defense, and the attackers were driven off, but Luit was clearly shaken. Within another seven weeks, Nikkie was alpha male, but utterly dependent on Yeroen’s aid. It should be noted that the Yeroen-Nikkie coalition was confined to encounters with Luit; in other circumstances, they were often hostile to one another.

Nikkie was a young and inexperienced leader. In fact, the keepers removed him from the group for a while to clam things down.

Chapter 3: Restless stability: Because Nikkie was inexperienced, he did not do what the previous leaders had done, namely maintain the peace. This lot fell instead to his ally, Yeroen. As a result of this, Yeroen was far more widely respected in the troop than Nikkie was, and in many ways was the power behind the throne. He was “greeted” by other chimps more than any other, even more than Nikkie.

Chapter 4: Sexual privileges: In general, the alpha male has the greatest sexual privileges. This is not due to female choice, since females (except Puist) generally consent to mate with any male when in estrus, but because dominant males can often prevent nondominant males from mating (though there is some furtive mating going on). During the first period of Nikkie’s leadership, though, Yeroen had the most matings, because the jealousy between Luit and Nikkie was so great that all Yeroen had to do was let one know that the other was mating and the whole thing was disrupted.

Chapter 5: Social mechanisms: Dependent rank is rank based on one’s relationships with high ranking individuals. Thus, one can be considerably elevated in rank when one’s patron is present.

Females have a dominance hierarchy just like males, but they have very few aggressive encounters, and the hierarchy is stable and uncontested.

The ability to be political is part of what is sometimes called social intelligence. To do what they do, chimps must be able to estimate the consequences of their social actions (e.g. Yeroen’s support of Nikkie’s quest for dominance). Social intelligence also implies the ability to recognize others as individuals, as well as triadic awareness, the recognition of not just the relation between oneself and another, but also one’s understanding of the relationship between two others and one’s own relationship between each of those.

Sharing is important. Once, the keepers gave a large pile of bananas to the troop. Yeroen behaved very aggressively in order to take control of the pile, but once he had it, he very carefully shared them out equally to everyone in the troop. Chimps will also cooperate, for example in escape attempts.

Chimps also have a well-developed sense of reciprocity. They reward those who help them and punish those who act against their interests.