International Journal of Primatology

, Volume 27, Issue 5, pp 1337–1364 | Cite as

Conflict Resolution in Chimpanzees and the Valuable-relationships Hypothesis


Reconciliation, or peaceful postconflict interaction, can restore the usual pattern of interaction between social partners after open conflict has disrupted it—i.e., it can resolve conflicts. Researchers have documented reconciliation in >20 primate species, but the tendency to reconcile typically varies among dyads and dyad classes. The valuable-relationships hypothesis proposes that differences in the value of social relationships account for much of this variation. Value depends on how likely partners are to act in ways that benefit each other, where the benefits are ultimately direct or indirect increases in fitness. Researchers have responded to studies that have tested predictions of the hypothesis with extensive, if not universal, support. For example, kin show higher conciliatory tendencies than nonkin in many species, and conciliatory tendencies between unrelated females are high in several cercopithecines in which nonkin agonistic support is important for rank acquisition and maintenance. However, most of the support is indirect, because we lack direct evidence on the link between assays of relationship value and fitness. Also, some studies have methodological weaknesses, e.g., analyses based on pooled data and insufficient sample sizes. I review evidence in favor of the hypothesis with special attention to studies that come closest to providing evidence for predicted fitness effects. I also present new data on postconflict interactions between adult male chimpanzees at Ngogo that show how often pairs of males formed coalitions and how much time they spent grooming influenced the likelihood that they would reconcile after conflicts, and that allies were particularly likely to reconcile and to do so by grooming each other. The most important future research direction is to integrate detailed data on conflict management, analyzed at the level of dyads, with long-term data on reproductive success, such as that now available from several study sites, on the same populations.


Alliances chimpanzees conflict resolution reconciliation valuable relationships 


  1. Alberts, S., and Altmann, J. (2004). Patterns of coalition formation by adult female baboons in Amboseli, Kenya. Anim. Behav. 67: 573–582.CrossRefGoogle Scholar
  2. Altmann, J., and Alberts, S. (2003). Variation in reproductive success viewed from a life history perspective in baboons. Am. J. Hum. Biol. 15: 401–409.PubMedCrossRefGoogle Scholar
  3. Arnold, K., and Barton, R. A. (2001). Post-conflict behavior of leaf monkeys (Trachypithecus obscurus). I. Reconciliation. Int. J. Primatol. 22: 243–266.CrossRefGoogle Scholar
  4. Arnold, K., and Whiten, A. (2001). Post-conflict behavior of wild chimpanzees (Pan troglodytes schweinfurthii) in the Budongo Forest, Uganda. Behaviour 138: 649–690.CrossRefGoogle Scholar
  5. Aureli, F. (1992). Post-conflict behavior among wild long-tailed macaques (Macaca fascicularis). Behav. Ecol. Sociobiol. 31: 329–337.CrossRefGoogle Scholar
  6. Aureli, F., Cords, M., and van Schaik, C. P. (2002). Conflict resolution following aggression in gregarious animals: A predictive framework. Anim. Behav. 64: 325–343.CrossRefGoogle Scholar
  7. Aureli, F., Das, M., and Veenema, H. C. (1993). Differential kinship effects on reconciliation in three species of macaques (Macaca fascicularis, M. fuscata, and M. sylvanus). J. Comp. Psychol. 11: 91–99.Google Scholar
  8. Aureli, F., van Schaik, C. P., and van Hooff, J. A. R. A. M. (1989). Functional aspects of reconciliation among captive long-tailed macaques (Macaca fascicularis). Am. J. Primatol. 19: 39–51.CrossRefGoogle Scholar
  9. Baker, K., and Smuts, B. B. (1994). Social relationships of female chimpanzees: Diversity between captive social groups. In Wrangham, W. W., McGrew, W. C., de Waal, F. B. M., and Heltne, P. G. (eds), Chimpanzee Cultures. Harvard University Press, Cambridge, MA, pp. 227–242.Google Scholar
  10. Barrett, L., and Henzi, S. P. (2001). The utility of grooming in baboon troops. In Noe, R., van Hooff, J. A. R. A. M., and Hammerstein, P. (eds), Economics in Nature: Social Dilemmas, Mate Choice, and Biological Markets. Cambridge University Press, Cambridge, UK, pp. 119–145.Google Scholar
  11. Boesch, C., and Boesch-Achermann, H. (2000). The Chimpanzees of the Tai Forest. Oxford University Press, Oxford.Google Scholar
  12. Butynski, T. (1990). Comparative ecology of blue monkeys (Cercopithecus mitis) in high- and low-density subpopulations. Ecol. Monogr. 60: 126.Google Scholar
  13. Casperd, J. M. (1997). The Evolution of Reconciliation Within the Primate Order. Unpublished Ph.D. Thesis, University of Liverpool.Google Scholar
  14. Castles, D., Aureli, F., and de Waal, F.B.M. (1996). Variation in conciliation tendency and relationship quality across groups of pigtail macaques. TAnim. Behav.T 52: 389--403.Google Scholar
  15. Castles, D., and Whiten, A. (1998). Post-conflict behavior of wild olive baboons. I. Reconciliation, redirection, and consolation. Ethology 104: 126147.Google Scholar
  16. Chapais, B. (1992). The role of alliances in the social inheritance of rank among female primates. In Harcourt, A. H., and de Waal, F. B. M. (eds.), Coalitions and Alliances in Humans and Other Animals. Oxford University Press, Oxford, pp. 29–60.Google Scholar
  17. Chapais, B. (2001). Primate nepotism: what is the explanatory value of kin selection? Int. J. Primatol. 22: 203–229.CrossRefGoogle Scholar
  18. Colmenares, F., and Lazaro-Perea, C. (1994). Greeting and grooming grooming during social conflicts in baboons. In Roeder, J. J., Thierry, B., Anderson, J. R., and Herrenschmidt, N. (eds.), Current Primatology, Vol. 2: Social Development, Learning, and Behavior, pp. 165–174. Université Louis Pasteur, Strasbourg.Google Scholar
  19. Cooper, M. A., Bernstein, I. S., and Hemelrijk, C. K. (2005). Reconciliation and relationship quality in Assamese macaques. Am. J. Primatol. 25: 269–282.CrossRefGoogle Scholar
  20. Cords, M. (1992). Post-conflict reunions and reconciliation in long-tailed macaques. Anim. Behav. 44: 57–61.CrossRefGoogle Scholar
  21. Cords, M. (1997). Friendship, alliances, reciprocity, and repair. In Whiten, A., and Byrne, R. W. (eds.), Machiavellian Intelligence II. Cambridge University Press, Cambridge, pp. 24–49.Google Scholar
  22. Cords, M., and Aureli, F. (1993). Patterns of reconciliation among juvenile long-tailed macaques. In Pereira, M., and Fairbanks, L. A. (eds.), Juvenile Primates. Oxford University Press, Oxford, pp. 271–284.Google Scholar
  23. Cords, M., and Aureli, F. (2000). Reconciliation and relationship qualities. In Aureli, F., and de Waal, F. B. M. (eds.), Natural Conflict Resolution, University of California Press, Berkeley, pp. 177–198.Google Scholar
  24. Cords, M., and Killen, M. (1998). Conflict resolution in human and nonhuman primates. In Langer, J., and Killen, M. (eds.), Piaget, Evolution, and Development. Lawrence Erlbaum, Mahwah, NJ, pp. 193–219.Google Scholar
  25. Cords, M., and Thurnheer, S. (1993). Reconciliation with valuable partners by long-tailed macaques. Ethology 93: 315–325.Google Scholar
  26. Demaria, C., and Thierry, B. (2001). A comparative study of reconciliation in rhesus and Tonkean macaques. Behaviour 138: 397–410.CrossRefGoogle Scholar
  27. de Waal, F. B. M. (1982). Chimpanzee Politics. Johns Hopkins University Press, Baltimore.Google Scholar
  28. de Waal, F.B.M. (1986). Integration of dominance and social bonding in primates. Quart. Rev. Biol. 61: 459--479.Google Scholar
  29. de Wall, F.B.M. (2000). The first kiss: Foundations of conflict resolution research in animals. In Aureli, F. and de Waal, F.B.M. (eds.), Natural Conflict Resolution. University of California Press, Berkeley, pp. 15--33.Google Scholar
  30. de Waal, F.B.M. and Aureli, F. (1996). Consolation, reconciliation, and a possible cognitive difference between macaques and chimpanzees. In Russon, A.E., Bard, K.A., and Parker, S.T. (eds.), Reaching Into Thought. Cambridge University Press, Cambridge, pp. 80-110.Google Scholar
  31. de Waal, F. B. M., and Aureli, F. (1997). Conflict resolution and distress alleviation in monkeys and apes. Ann. NY Acad. Sci. 807: 317–328.Google Scholar
  32. de Waal, F. B. M., and van Roosmalen, A. (1979). Reconciliation and consolation among chimpanzees. Behav. Ecol. Sociobiol. 5: 55–66.CrossRefGoogle Scholar
  33. de Waal, F. B. M., and Yoshihara, D. (1983). Reconciliation and redirected affection in rhesus monkeys. Behaviour 85: 224–241.Google Scholar
  34. Fuentes, A., Malone, N., Sanz, C., Matheson, M., and Vaughan, L. (2002). Conflict and post-conflict behavior in a small group of chimpanzees. Primates 43: 223–236.PubMedGoogle Scholar
  35. Grinnell, J., Packer, C., and Pusey, A. E. (1995). Cooperation in male lions: Kin selection, reciprocity, or mutualism? Anim. Behav. 49: 95–105.CrossRefGoogle Scholar
  36. Gros-Louis, J., Manson, J. H., and Perry, S. (2003). Violent coalitionary attacks and intraspecific killing in wild white-faced capuchin monkeys (Cebus capucinus). Primates 44: 341–346.PubMedCrossRefGoogle Scholar
  37. Harcourt, A. H. (1987). Dominance and fertility in female primates. J. Zool. Lond. 213: 471–487.CrossRefGoogle Scholar
  38. Hemelrijk, C. K. (1990). Models of, and tests for, reciprocity, unidirectionality, and other social interaction patterns at group level. Anim. Behav. 39: 1013-1029.Google Scholar
  39. Hemelrijk, C. K. (1991). A matrix partial correlation test used in correlations of reciprocity and other social interaction patterns at group level. J. Theor. Biol. 143: 405–420.Google Scholar
  40. Henzi, P., and Barrett, L. (2003). Evolutionary ecology, sexual conflict, and behavioral differentiation among baboon populations. Evol. Anthropol. 12: 217–230.CrossRefGoogle Scholar
  41. Judge, P. (1991). Dyadic and triadic reconciliation in pigtail macaques (Macaca nemestrina). Am. J. Primatol. 23: 225–237.CrossRefGoogle Scholar
  42. Kappeler, P., and van Schaik, C. P. (1992). Methodological and evolutionary aspects of reconciliation in primates. Ethology 92: 51–69.Google Scholar
  43. Koyama, M. (2001). The long-term effects of reconciliation in Japanese macaques Macaca fuscata. Ethology 107: 975–987.CrossRefGoogle Scholar
  44. Kummer, H. (1978). On the value of social relationships to nonhuman primates: A heuristic scheme. Soc. Sci. Infor. 17: 687–705.Google Scholar
  45. Kutsukake, N., and Castles, D. L. (2004). Reconciliation and post-conflict third-party affiliation among wild chimpanzees in the Mahale Mountains, Tanzania. Primates 45: 157–165.PubMedCrossRefGoogle Scholar
  46. Lewis, R. J. (2002). Beyond dominance: The importance of leverage. Quart. Rev. Biol. 77: 149–164.PubMedCrossRefGoogle Scholar
  47. Lwanga, J. S., Butynski, T., and Struhsaker, T. T. (2000). Tree population dynamics in Kibale National Park, Uganda 1975–1998. Afr. J. Ecol. 38: 238–247.CrossRefGoogle Scholar
  48. Majolo, B., Ventura, R., and Koyama, N. (2005). Postconflict behavior among male Japanese macaques. Int. J. Primatol. 26: 321–336.CrossRefGoogle Scholar
  49. Manson, J. H., Perry, S., and Stahl, D. (2005). Reconciliation in wild white-faced capuchins (Cebus capucinus). Am. J. Primatol. 65: 205–219.PubMedCrossRefGoogle Scholar
  50. Manson, J. H., Rose, L. M., Perry, S., and Gros-Louis, J. (1999). Dynamics of female-female relationships in wild Cebus capucinus: Data from two Costa Rican sites. Int. J. Primatol. 20: 679–706.CrossRefGoogle Scholar
  51. Nishida, T. (1983). Alpha status and agonistic alliance in wild chimpanzees (Pan troglodytes schweinfurthii). Primates 24: 318–336.CrossRefGoogle Scholar
  52. Nishida, T., and Hosaka, K. (1996). Coalition strategies among adult male chimpanzees of the Mahale Mountains, Tanzania. In McGrew, W. A., Marchant, L. A., and Nishida, T. (eds.), Great Ape Societies. Cambridge University Press, Cambridge, pp. 114–134.Google Scholar
  53. Palagi, E., Paoli, T., and Tarli, S. B. (2004). Reonciliation and consolation in captive bonobos. Am. J. Primatol. 62: 15–30.PubMedCrossRefGoogle Scholar
  54. Palombit, R. A., Seyfarth, R. M., and Cheney, D. L. (1997). The adaptive value of “friendships” to female baboons: Experimental and observational evidence. Anim. Behav. 54: 599–614.PubMedCrossRefGoogle Scholar
  55. Perry, S. (1996). Female-female social relationships in wild white-faced capuchin monkeys, Cebus capucinus. Am. J. Primatol. 40: 167–182.CrossRefGoogle Scholar
  56. Perry, S. (1997). Male-female social relationships in wild white-faced capuchin monkeys, Cebus capucinus. Behaviour 134: 477–510.Google Scholar
  57. Perry, S. (1998). Male-male social relationships in wild white-faced capuchins, Cebus capucinus. Behaviour 135: 1–34.Google Scholar
  58. Preuschoft, S., Wang, X., Aureli, F., and de Waal, F. B. M. (2002). Reconciliation in captive chimpanzees: A re-evaluation with controlled methods. Int. J.Primatol. 23: 29–50.CrossRefGoogle Scholar
  59. Seyfarth, R. M. (1977). A model of social grooming among adult female monkeys. J. Theor. Biol. 65: 671–698.PubMedCrossRefGoogle Scholar
  60. Silk, J. B. (1997). The function of peaceful post-conflict contacts among primates. Primates 38: 265–279.CrossRefGoogle Scholar
  61. Silk, J. B., Alberts, S. C., and Altmann, J. (2003). Social bonds of female baboons enhance infant survival. Science 302: 1231–1234.PubMedCrossRefGoogle Scholar
  62. Silk, J. B. Alberts, S. C., and Altmann, J. (2004). Patterns of coalition formation by adult female baboons in Amboseli, Kenya. Anim. Behav. 67: 573--582.Google Scholar
  63. Silk, J. B., Cheney, D. L., and Seyfarth, R. M. (1996). The form and function of post-conflict interactions between female baboons. Anim. Behav. 52: 259–268.CrossRefGoogle Scholar
  64. Sommer, V., Denham, A., and Little, K. (2002). Post-conflict behavior of wild Indian langur monkeys: Avoidance of opponents but rarely affinity. Anim. Behav. 63: 637–648.CrossRefGoogle Scholar
  65. Struhsaker, T. T. (1997). The Ecology of an African Rainforest. University Press of Florida, Gainesville.Google Scholar
  66. Takahata, Y., Huffman, M. A., Suzuki, S., Koyama, N., and Yamagiwa, J. (1999). Why dominants do not consistently attain high mating and reproductive success: A review of longitudinal Japanese macaque studies. Primates 40: 143–158.Google Scholar
  67. Thierry, B. (1990). L’état d’équilibre entre comportements agonistiques chez un groupe de macaques Japonais (Macaca fuscata). Compte Rend. Acad. Sci. Paris 310(III): 35–40.Google Scholar
  68. Thierry, B. (2000). Covariation of conflict management patterns across macaque species. In Aureli, F., and de Waal, F. B. M. (eds.), Natural Conflict Resolution. University of California Press, Berkeley, pp. 106–128.Google Scholar
  69. Tutin, C. E. G. (1979). Mating patterns and reproductive strategies in a community of wild chimpanzees (Pan troglodytes schweinfurthii). Behav. Ecol. Sociobiol. 6: 29--38.Google Scholar
  70. van Hooff, J. A. R. A. M., and van Schaik, C. P. (1994). Male bonds: affiliative relationships among nonhuman primate males. Behaviour 130: 309–337.Google Scholar
  71. van Noordwijk, M. A., and van Schaik, C. P. (1999). The effects of dominance rank and group size on female lifetime reproductive success in wild long-tailed macaques (Macaca fascicularis). Primates 40: 105–130.Google Scholar
  72. van Schaik, C. P. (1989). The ecology of social relationships amongst female primates. In Standen, V., and Foley, R. A. (eds.), Comparative Socioecology. Blackwell, London, pp. 195–218.Google Scholar
  73. van Schaik, C. P., and Aureli, F. (2000). The natural history of valuable social relationships in primates. In Aureli, F., and de Waal, F. B. M. (eds.), Natural Conflict Resolution. University of California Press, Berkeley, pp. 307–333.Google Scholar
  74. Veenema, H. C., Das, M., and Aureli, F. (1994). Methodological improvements for the study of reconciliation. Behav. Process. 31: 29–38.CrossRefGoogle Scholar
  75. Watts, D. P. (1995). Post-conflict events in wild mountain gorillas (Mammalia, Hominoidea) I. Social interactions between opponents. Ethology 100: 139–157.CrossRefGoogle Scholar
  76. Watts, D. P. (1998). Coalitionary mate guarding by male chimpanzees at Ngogo, Kibale National Park, Uganda. Behav. Ecol. Sociobiol. 44: 43–55.CrossRefGoogle Scholar
  77. Watts, D. P., Colmenares, F., and Arnold, K. (2000). Redirection, consolation, and male policing. In Aureli, F., and de Waal, F. B. M. (eds.), Natural Conflict Resolution. University of California Press, Berkeley, pp. 281–301.Google Scholar
  78. Watts, D. P., and Mitani, J. C. (2001). Boundary patrols and intergroup aggression in wild chimpanzees. Behaviour 138: 299–327.CrossRefGoogle Scholar
  79. Watts, D. P., Muller, M., Amsler, S., Mbabazi, G., and Mitani, J. C. (2006). Lethal intergroup aggression by chimpanzees in the Kibale National Park, Uganda. Amer. J. Primatol. 68: 161-180.Google Scholar
  80. Williams, J. M., Oehlert, G. W., Carlis, J. V, and Pusey, A. E. (2004). Why do male chimpanzees defend a group range? Anim. Behav. 68: 523–532.CrossRefGoogle Scholar
  81. Williams, J. M., Pusey, A. E., Carlis, J. V., Fram, B. P., and Goodall, J. (2002). Female competition and male territorial behavior influence female chimpanzees’ ranging patterns. Anim. Behav. 63: 347–360.CrossRefGoogle Scholar
  82. Wilson, M. L., Hauser, M. D., and Wrangham, R. W. (2001). Does participation in intergroup depend on numerical assessment, range location, or rank for wild chimpanzees? Anim. Behav. 61: 1203–1216.CrossRefGoogle Scholar
  83. Wilson, M. L., and Wrangham, R. W. (2003). Intergroup relations in chimpanzees. Annu. Rev. Anthropol. 32: 363–392.CrossRefGoogle Scholar
  84. Wittig, R. M., and Boesch, C. (2003). “Decision making” in conflicts of wild chimpanzees (Pan troglodytes): An extension of the relational model. Behav. Ecol. Sociobiol. 54: 491–504.CrossRefGoogle Scholar
  85. Wrangham, R. W. (1999). Evolution of coalitionary killing. Yrbk. Phys. Anthro. 42: 1–30.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  1. 1.Department of AnthropologyYale UniversityNew HavenUSA

Personalised recommendations