Frans de Waal's 'Peacemaking Among Primates'
In his book Peacemaking Among Primates, Dutch ethologist Frans de Waal reports his observations of a broad pattern of primate social behavior that he terms "reconciliation." Reconciliation, as de Waal defines it for non-human primates, is the occurrence of "friendly" body contact between former adversaries. In order for it to be measured scientifically, reconciliation must occur within a certain time period after an aggressive encounter. The time limits in two of de Waal's studies, both of primate groups in captivity, were 10 and 30 minutes, although he suspects that chimpanzees sometimes take hours or even up to a day to reconcile. In the four species that de Waal observed (common chimpanzees, bonobos, Rhesus monkeys, and stump-tailed monkeys), there was a wide variety of both aggressive and conciliatory acts. Aggressive acts included chasing, hitting, biting, trampling, screaming, and threatening displays, while reconciliation was expressed by gentler physical contact, ranging from a brief brushing together of fur as one animal passed another to mutual sexual stimulation.
Reconciliation in non-human primates reaches its peak of subtlety and complexity in the chimpanzees, Pan troglodytes (the common chimp) and Pan paniscus (the bonobo). The highly developed intelligence and social awareness of these species give rise to intricate dramas of conflict and peacemaking. Observation of a group of captive common chimps over a period of several years revealed that 40% of their aggressive encounters were followed by reconciliation within half an hour. Males reconciled with males 47% of the time, while the rate for females with females was 18%. The incidence of reconciliation between the sexes was intermediate between those two values. The characteristic conciliatory act in this species is the mouth-to-mouth kiss, although an outstretched arm and hand, eye contact, vocalization, grooming, hugging, mounting, and genital touching are also seen. Social groups of common chimpanzees maintain a dominance hierarchy, especially noticeable among males, and, while aggression is usually initiated by a more dominant individual, the initiative for reconciliation is divided equally between dominants and subordinates. Often a dominant will require submissive behavior from a former adversary before consenting to reconcile. Many other variations on the basic theme of reconciliation have been observed in common chimps. On several occasions, de Waal saw one chimp invite a former opponent to reconcile, only to renew the attack when the other chimp approached. Sometimes a female will act as mediator between two males who, although they seem to want reconciliation, are reluctant to make the first move. Another way males may "save face" is to pretend interest in an imaginary or insignificant object. This allows them to approach each other without having to explicitly acknowledge their recent conflict.
Bonobos have not been studied as much as common chimps, but a few differences have been observed in their styles of reconciliation. Peacemaking in bonobos occurs in the context of a somewhat different social structure. In contrast to chimpanzee society, bonobos have no central group of bonded males, and there is no clear dominance of males over females. Bonobos, at least in captivity, are on the whole more gentle than common chimps. Their aggressive encounters are usually very short-lived, and do not escalate into the serious violence sometimes seen in P. troglodytes. In de Waal's observations, reconciliation occurred at a higher rate among bonobos than it did among common chimps. Also, bonobo reconciliations were initiated primarily by the more dominant individual, which is different than the pattern mentioned above. Since, in both species, it's usually the dominant who started the fight in the first place, bonobos are like humans in that it is the "guilty" party who pleads forgiveness, not the victim. But the most characteristic aspect of bonobo reconciliation is its incorporation of sexual activity, which occurs between individuals of every combination of sex and age. Bonobos are much more sexually active in general than are common chimps, and they seem to use sex as a release of tension in competitive situations. In fact, de Waal thinks that they have gone one step beyond reconciliation, in that they actually use sex to forestall violence, rather than just to repair it.
De Waal concludes that the complexity and diversity of chimpanzee and bonobo behavior are evidence that these animals are not mere automatons obeying instinctual drives—on the contrary, they are aware of themselves, of the past and future, of who their friends, relatives, and enemies are, and of the importance of maintaining good relationships with others. This high level of consciousness must have evolved slowly, step by step, as, over the millennia, early primates who tried group living had greater reproductive success than less social individuals. There are benefits to social life, but there are also costs. A major cost is the greater competition for mates and resources that results from increased population density. Aggression helps an individual compete, but unchecked aggression would lead to disruption of the social structure and dispersal of the group. Therefore, techniques of controlling aggression are important. Reconciliation is just one pattern of aggression management. Other methods include restraint by a third party, the maintenance of dominance hierarchies, pre-conflict appeasement, and attacks on outsiders. Sometimes aggression escapes management and escalates into fatal violence. But, for the most part, when the inevitable clashes arise, this extreme is avoided, and it appears that the primate ability to kiss and make up may be one of the more important reasons why.
Reconciliation in non-human primates reaches its peak of subtlety and complexity in the chimpanzees, Pan troglodytes (the common chimp) and Pan paniscus (the bonobo). The highly developed intelligence and social awareness of these species give rise to intricate dramas of conflict and peacemaking. Observation of a group of captive common chimps over a period of several years revealed that 40% of their aggressive encounters were followed by reconciliation within half an hour. Males reconciled with males 47% of the time, while the rate for females with females was 18%. The incidence of reconciliation between the sexes was intermediate between those two values. The characteristic conciliatory act in this species is the mouth-to-mouth kiss, although an outstretched arm and hand, eye contact, vocalization, grooming, hugging, mounting, and genital touching are also seen. Social groups of common chimpanzees maintain a dominance hierarchy, especially noticeable among males, and, while aggression is usually initiated by a more dominant individual, the initiative for reconciliation is divided equally between dominants and subordinates. Often a dominant will require submissive behavior from a former adversary before consenting to reconcile. Many other variations on the basic theme of reconciliation have been observed in common chimps. On several occasions, de Waal saw one chimp invite a former opponent to reconcile, only to renew the attack when the other chimp approached. Sometimes a female will act as mediator between two males who, although they seem to want reconciliation, are reluctant to make the first move. Another way males may "save face" is to pretend interest in an imaginary or insignificant object. This allows them to approach each other without having to explicitly acknowledge their recent conflict.
Bonobos have not been studied as much as common chimps, but a few differences have been observed in their styles of reconciliation. Peacemaking in bonobos occurs in the context of a somewhat different social structure. In contrast to chimpanzee society, bonobos have no central group of bonded males, and there is no clear dominance of males over females. Bonobos, at least in captivity, are on the whole more gentle than common chimps. Their aggressive encounters are usually very short-lived, and do not escalate into the serious violence sometimes seen in P. troglodytes. In de Waal's observations, reconciliation occurred at a higher rate among bonobos than it did among common chimps. Also, bonobo reconciliations were initiated primarily by the more dominant individual, which is different than the pattern mentioned above. Since, in both species, it's usually the dominant who started the fight in the first place, bonobos are like humans in that it is the "guilty" party who pleads forgiveness, not the victim. But the most characteristic aspect of bonobo reconciliation is its incorporation of sexual activity, which occurs between individuals of every combination of sex and age. Bonobos are much more sexually active in general than are common chimps, and they seem to use sex as a release of tension in competitive situations. In fact, de Waal thinks that they have gone one step beyond reconciliation, in that they actually use sex to forestall violence, rather than just to repair it.
De Waal concludes that the complexity and diversity of chimpanzee and bonobo behavior are evidence that these animals are not mere automatons obeying instinctual drives—on the contrary, they are aware of themselves, of the past and future, of who their friends, relatives, and enemies are, and of the importance of maintaining good relationships with others. This high level of consciousness must have evolved slowly, step by step, as, over the millennia, early primates who tried group living had greater reproductive success than less social individuals. There are benefits to social life, but there are also costs. A major cost is the greater competition for mates and resources that results from increased population density. Aggression helps an individual compete, but unchecked aggression would lead to disruption of the social structure and dispersal of the group. Therefore, techniques of controlling aggression are important. Reconciliation is just one pattern of aggression management. Other methods include restraint by a third party, the maintenance of dominance hierarchies, pre-conflict appeasement, and attacks on outsiders. Sometimes aggression escapes management and escalates into fatal violence. But, for the most part, when the inevitable clashes arise, this extreme is avoided, and it appears that the primate ability to kiss and make up may be one of the more important reasons why.
