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Chimpanzees’ Bystander Reactions to Infanticide

An Evolutionary Precursor of Social Norms?

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Abstract

Social norms—generalized expectations about how others should behave in a given context—implicitly guide human social life. However, their existence becomes explicit when they are violated because norm violations provoke negative reactions, even from personally uninvolved bystanders. To explore the evolutionary origin of human social norms, we presented chimpanzees with videos depicting a putative norm violation: unfamiliar conspecifics engaging in infanticidal attacks on an infant chimpanzee. The chimpanzees looked far longer at infanticide scenes than at control videos showing nut cracking, hunting a colobus monkey, or displays and aggression among adult males. Furthermore, several alternative explanations for this looking pattern could be ruled out. However, infanticide scenes did not generally elicit higher arousal. We propose that chimpanzees as uninvolved bystanders may detect norm violations but may restrict emotional reactions to such situations to in-group contexts. We discuss the implications for the evolution of human morality.

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References

  • Aureli, F., & van Schaik, C. (1991). Post-conflict behaviour in long-tailed macaques (Macaca fascicularis): II Coping with uncertainty. Ethology, 89, 101–114.

    Article  Google Scholar 

  • Baker, A. C., & Aureli, F. (1997). Behavioural indicators of anxiety: an empirical test in chimpanzees. Behaviour, 134, 1031–1050.

    Article  Google Scholar 

  • BergmanT, J., Beehner, J. C. L. C. D., & Seyfarth, R. M. (2003). Hierarchical classification by rank and kinship in baboons. Science, 302, 1234–1236.

    Article  Google Scholar 

  • Boehm, C. (1994). Pacifying interventions at Arnhem Zoo and Gombe. In R. W. Wrangham, W. C. McGrew, F. B. M. de Waal, & P. G. Heltne (Eds.), Chimpanzee cultures (pp. 211–226). Cambridge: Harvard University Press.

    Google Scholar 

  • Boesch, C. (2009). The real chimpanzee. Cambridge: Cambridge University Press.

    Google Scholar 

  • Bowles, S., & Gintis, H. (2004). Persistent parochialism: trust and exclusion in ethnic networks. Journal of Economic Behavior and Organization, 55, 1–23.

    Article  Google Scholar 

  • Bräuer, J., & Hanus, D. (2012). Fairness in non-human primates? Social Justice Research, 25(3), 256–276.

    Article  Google Scholar 

  • Brosnan, S. F., & de Waal, F. B. (2014). Evolution of responses to (un) fairness. Science, 346(6207), 1251776.

    Article  Google Scholar 

  • Cacchione, T., & Burkart, J. M. (2012). Dissociation between seeing and acting: insights from common marmosets (Callithrix jacchus). Behavioural Processes, 89, 52–60.

    Article  Google Scholar 

  • Cacchione, T., & Krist, H. (2004). Recognizing impossible object relations: intuitions about support in chimpanzees (Pan troglodytes). Journal of Comparative Psychology, 118, 140–148.

    Article  Google Scholar 

  • Cheney, D. L., & Seyfarth, R. M. (1999). Recognition of other individuals’ social relationships by female baboons. Animal Behaviour, 58, 67–75.

    Article  Google Scholar 

  • Darwin, C. (1982). The descent of man, and selection in relation to sex. Princeton: Princeton University Press.

    Google Scholar 

  • Das, M., Penke, Z., & Van Hooff, J. A. R. A. M. (1998). Postconflict affiliation and stress-related behaviour of long-tailed macaque aggressors. International Journal of Primatology, 19, 53–71.

    Article  Google Scholar 

  • de Waal, F. B. M. (1982). Chimpanzee politics: Power and sex among apes. London: Unwin Paperbacks.

    Google Scholar 

  • de Waal, F. B. M. (1984). Sex differences in the formation of coalitions among chimpanzees. Ethology and Sociobiology, 5, 239–255.

    Article  Google Scholar 

  • de Waal, F. B. M. (1991). The chimpanzee’s sense of social regularity and its relation to the human sense of justice. American Behavioral Scientist, 34, 335–349.

    Article  Google Scholar 

  • de Waal, F. B. M. (1996). Good natured: The origins of right and wrong in humans and other animals. Cambridge: Harvard University Press.

    Google Scholar 

  • de Waal, F. B. M. (2006). Primates and philosophers: How morality evolved. Princeton: Princeton University Press.

    Google Scholar 

  • de Waal, F. B. M., & Hoekstra, J. A. (1980). Contexts and predictability of aggression in chimpanzees. Animal Behaviour, 28, 929–937.

    Article  Google Scholar 

  • de Waal, F. B. M., & van Hooff, J. A. R. A. M. (1981). Side-directed communication and agonistic anteractions in chimpanzees. Behaviour, 77, 164–198.

    Article  Google Scholar 

  • de Waal, F. B. M., & van Roosmalen, A. (1979). Reconciliation and consolation among chimpanzees. Behavioral Ecology and Sociobiology, 5, 55–66.

    Article  Google Scholar 

  • Ehrlich, P. R., & Levin, S. A. (2005). The evolution of norms. PLoS Biology, 3, 0943–0948.

    Article  Google Scholar 

  • Ellikson, R. C. (2001). The evolution of social norms: A perspective from the legal academy. In M. Hechter & K. D. Opp (Eds.), Social norms (pp. 35–75). New York: Russell Sage.

    Google Scholar 

  • Fehr, E., & Fischbacher, U. (2004). Third-party punishment and social norms. Evolution and Human Behavior, 25, 63–87.

    Article  Google Scholar 

  • Fehr, E., & Gächter, S. (2002). Altruistic punishment in humans. Nature, 415, 137–140.

    Article  Google Scholar 

  • Flack, J. C., & de Waal, F. B. M. (2002). Any animal whatever: Darwinian building blocks of morality in monkeys and apes. In L. D. Katz (Ed.), Evolutionary origins of rorality: Cross-disciplinary perspectives (pp. 1–29). Thorverton: Imprint Academic.

  • Flack, J. C., Jeannotte, L. A., & de Waal, F. B. M. (2004). Play signaling and the perception of social rules by juvenile chimpanzees (Pan troglodytes). Journal of Comparative Psychology, 118, 149–159.

    Article  Google Scholar 

  • Flack, J. C., de Waal, F. B. M., & Krakauer, D. C. (2005). Social structure, robustness, and policing cost in a cognitively sophisticated species. American Naturalist, 165(5), E126–E139.

    Article  Google Scholar 

  • Flack, J. C., Girvan, M., de Waal, F. B. M., & Krakauer, D. C. (2006). Policing stabilizes constructions of social niches in primates. Nature, 439, 426–429.

    Article  Google Scholar 

  • Fraser, O. N., & Aureli, F. (2008). Reconciliation, consolation and postconflict behavioral specificity in chimpanzees. American Journal of Primatology, 70, 1114–1123.

    Article  Google Scholar 

  • Fraser, O. N., Stahl, D., & Aureli, F. (2008). Stress reduction through consolation in chimpanzees. Proceedings of the National Academy of Sciences, 105, 8557–8562.

    Article  Google Scholar 

  • Goodall, J. (1971). In the shadow of man. Boston: Houghton Mifflin.

    Google Scholar 

  • Goodall, J. (1977). Infant killing and cannibalism in free-living chimpanzees. Folia Primatologica, 28, 259–282.

    Article  Google Scholar 

  • Goodall, J. (1983). Order without law. In M. Gruter & P. Bohannan L. (Eds.), Law, Biology and Culture (pp 50–62). Santa Barbara: Ross-Erikson.

  • Goodall, J. (1986). The chimpanzees of gombe: Patterns of behavior. Cambridge: The Belknap Press of Harvard University.

    Google Scholar 

  • Haidt, J. (2007). The new synthesis in moral psychology. Science, 316, 998–1002.

    Article  Google Scholar 

  • Hamai, M., Nishida, T., Takasaki, H., & Turner, L. A. (1992). New records of within-group infanticide and cannibalism in wild chimpanzees. Primates, 33, 151–162.

    Article  Google Scholar 

  • Hamlin, J. K., Wynn, K., & Bloom, P. (2007). Social evaluation by preverbal infants. Nature, 450, 557–559.

    Article  Google Scholar 

  • Hechter, M., & Opp, K. D. (Eds.) (2001). Social norms. New York: The Russell Sage Foundation.

  • Horne, C. (2001). Sociological serspectives on the emergence on norms. In M. Hechter & K. D. Opp (Eds.), Social norms (pp. 3–34). New York: The Russell Sage Foundation.

    Google Scholar 

  • Jasso, G. (2001). Rule finding about rule making: Comparison processes and the making of rules. In M. Hechter & K. D. Opp (Eds.), Social norms (pp. 348–394). New York: The Russell Sage Foundation.

    Google Scholar 

  • Killen, M., & de Waal, F. B. M. (2000). The evolution and development of morality. In F. Aureli & F. B. M. de Waal (Eds.), Natural conflict resolution (pp. 352–372). London: University of California Press.

    Google Scholar 

  • Koski, S. E., & Sterck, E. H. M. (2009). Post-conflict third-party affiliation in chimpanzees: what’s in it for the third party? American Journal of Primatology, 71, 1–10.

    Article  Google Scholar 

  • Kuhlmeier, V., Wynn, K., & Bloom, P. (2003). Attribution of dispositional states by 12-month-olds. Psychological Science, 14, 402–408.

    Article  Google Scholar 

  • Lang, P. J., Bradley, M. M., Cuthbert, M. M. (1997). Motivated attention: affect, activation and action. In P. J. Lang, R. F. Simons & M. T. Balaban (Eds.), Attention and orienting: Sensory and motivational processes (pp. 97–136). Hillsdale: Lawrence Erlbaum Associates.

  • Melis, A. P., Warneken, F., Jensen, K., Schneider, A. C., Call, J., & Tomasello, M. (2011). Chimpanzeeshelp conspecifics obtain food and non-food items. Proceedings of the Royal Society B, 278, 1405–1413.

    Article  Google Scholar 

  • Murray, C. M., Wroblewski, E., & Pusey, A. E. (2007). New case of intragroup infanticide in the chimpanzees of Gombe National Park. International Journal of Primatology, 28, 23–37.

    Article  Google Scholar 

  • Nishida, T., Kano, T., Goodall, J., Mcgrew, W. C., & Nakamura, M. (1999). Ethogram and ethnography of Mahale chimpanzees. Anthropological Science, 107, 141–188.

    Article  Google Scholar 

  • Parr, L. A. (2001). Cognitive and physiological markers of emotional awareness. Animal Cognition, 4, 223–229.

    Article  Google Scholar 

  • Parr, L. A., & Hopkins, W. D. (2000). Brain temperature asymmetries and emotional perception in chimpanzees, Pan troglodytes. Physiology and Behavior, 71, 363–371.

    Article  Google Scholar 

  • Poss, S. R., & Rochat, P. (2003). Referential understanding of videos in chimpanzees (Pan troglodytes), aoangutans (Pongo pygmaeus), and children (Homo sapiens). Journal of Comparative Psychology, 177, 420–428.

    Article  Google Scholar 

  • Preston, S., & de Waal, F. B. M. (2002). Empathy: its ultimate and proximate bases. Behavioral and Brain Sciences, 25, 1–72.

    Google Scholar 

  • Rudolf von Rohr, C., Burkart, J. M., & van Schaik, C. P. (2011). Evolutionary precursors of social norms in chimpanzees: a new approach. Biology and Philosophy, 26, 1–30. doi:10.1007/s10539-010-9240-4.

    Article  Google Scholar 

  • Rudolf von Rohr, C., Koski, S. E., Burkart, J. M., Caws, C., Fraser, O. N., Ziltener, A., et al. (2012). Impartial third-party interventions in captive chimpanzees: a reflection of community concern. PLoS ONE, 7, e32494.

    Article  Google Scholar 

  • Sakamaki, T., Itoh, N., & Nishida, T. (2001). An attempted within-group infanticide in wild chimpanees. Primates, 42(4), 359–366.

    Article  Google Scholar 

  • Santos, L. R., & Hauser, M. D. (2002). A non-human primate’s understanding of solidity: dissociations between seeing and acting. Developmental Science, 5, F1–F7.

    Article  Google Scholar 

  • Sober, E., & Wilson, D. S. (1998). Unto others—the evolution and psychology of unselfish behavior. Cambridge: Harvard University Press.

    Google Scholar 

  • Townsend, S. W., Slocombe, K. E., Thompson, M. E., & Zuberbühler, K. (2007). Female-led infanticide in wild chimpanzees. Current Biology, 17, R355–R356.

    Article  Google Scholar 

  • Troisi, A. (2002). Displacement activities as a behavioral measure of stress in nonhuman primates and human subjects. Stress, 5, 47–54.

    Article  Google Scholar 

  • van Schaik, C. P. (2000). Infanticide by male primates: The sexual selection hypothesis revisited. In C. P. van Schaik & C. H. Janson (Eds.), Infanticide by males and its implications (pp. 27–61). Cambridge: Cambridge University Press.

  • van Schaik, C. P., Burkart, J. M., Jaeggi, A. V., & Rudolf von Rohr, C. (2014). Morality as a biological adaptation—An evolutionary model based on the lifestyle of human foragers. In M. Christen, C. van Schaik, J. Fischer, M. Huppenbauer & C. Tanner (Eds.), Empirically informed ethics: Morality between facts and norms (pp. 65–84). Cham: Springer.

  • Wang, S. H., Baillargeon, R., & Brueckner, L. (2004). Young infants’ reasoning about hidden objects: evidence from violation-of-expectation tasks with test trials only. Cognition, 93, 167–198.

    Article  Google Scholar 

  • Warneken, F., & Tomasello, M. (2006). Altruistic helping in human infants and young chimpanzees. Science, 311, 1301–1303. doi:10.1126/science.1121448.

    Article  Google Scholar 

  • Warneken, F., Hare, B., Melis, A. P., Hanus, D., & Tomasello, M. (2007). Spontaneous altruism by chimpanzees and young children. PLoS Biology, 5, e184.

    Article  Google Scholar 

  • Wrangham, R. W. (1999). Evolution of coalitionary killing. Yearbook of Physical Anthropology, 110, 1–30.

    Article  Google Scholar 

  • Yamamoto, S., Humle, T., & Tanaka, M. (2009). Chimpanzees help each other upon request. PLoS One, 4, e7416.

    Article  Google Scholar 

  • Young, H. P. (2002). The power of norms. In P. Hammerstein (Ed.), Genetic and cultural evolution of cooperation (pp. 389–399). Cambridge: The MIT Press.

    Google Scholar 

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Acknowledgments

We thank Elizabeth Lonsdorf and Ian Gilby for generously sharing their film footage with us, and Igor Drieghe for his help with the video standardization. We also thank the Walter Zoo in Gossau and Zoo Basel, and especially animal keepers Angela Widmer and Stefan Lopez for their cooperation during the experiments, and Corinne Sober and Angela Ziltener for assistance with the experiments and Sereina Graber and Alexandra Kropac for assistance with the data analysis. We also thank Sonja Koski and two anonymous referees for fruitful discussions and comments on an earlier version of this manuscript. This work was funded by the University Priority Research Program in Ethics at the University of Zurich and the A. H. Schultz-Foundation of the Anthropological Institute and Museum at the University of Zurich.

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Authors and Affiliations

  1. Anthropological Institute & Museum, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland

    Claudia Rudolf von Rohr, Carel P. van Schaik, Alexandra Kissling & Judith M. Burkart

  2. University Research Priority Program in Ethics, University of Zurich, Zurich, Switzerland

    Claudia Rudolf von Rohr

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  1. Claudia Rudolf von Rohr
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  2. Carel P. van Schaik
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  4. Judith M. Burkart
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Correspondence to Judith M. Burkart.

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von Rohr, C.R., van Schaik, C.P., Kissling, A. et al. Chimpanzees’ Bystander Reactions to Infanticide. Hum Nat 26, 143–160 (2015). https://doi.org/10.1007/s12110-015-9228-5

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