Incidental ostracism emerges from simple learning mechanisms



Ostracism, or social exclusion, is widespread and associated with a range of detrimental psychological and social outcomes. Ostracism is typically explained as instrumental punishment of free-riders or deviants. However, this instrumental account fails to explain many of the features of real-world ostracism, including its prevalence. Here we hypothesized that ostracism can emerge incidentally (non-instrumentally) when people choose partners in social interactions, and that this process is driven by simple learning mechanisms. We tested this hypothesis in four experiments (n = 456) with economic games in dynamic social networks. Contrary to the instrumental account of ostracism, we find that the targets of ostracism are not primarily free-riders. Instead, incidental initial variability in choosing partners for social interactions predicts later ostracism better than the instrumental account. Using computational modelling, we show that simple reinforcement learning mechanisms explain the incidental emergence of ostracism, and that they do so better than a formalization of the instrumental account. Finally, we leveraged these reinforcement learning mechanisms to experimentally reduce incidental ostracism. Our results demonstrate that ostracism is more incidental than previously assumed and can arise from basic forms of learning. They also show that the same mechanisms that result in incidental ostracism can help to reduce its emergence.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Experimental design.
Fig. 2: Prediction of late popularity by early popularity in four different real-world social networks.
Fig. 3: Objective and subjective ostracism in experiment 1.
Fig. 4: Incidental, path-dependent ostracism in the prisoner’s dilemma game of experiment 1 and in the pure coordination game of experiment 2.
Fig. 5: Comparison between emergence and instrumental models in experiment 1.
Fig. 6: Model validation based on generative performance.
Fig. 7: Model generalizability.
Fig. 8: Reduction in objective and subjective ostracism by causal manipulation of path dependence in experiments 3 and 4.


  1. 1.

    Williams, K. D. Ostracism. Annu. Rev. Psychol. 58, 425–452 (2007).

    Article  PubMed  Google Scholar 

  2. 2.

    Wesselmann, E. D. & Williams, K. D. Social life and social death: inclusion, ostracism, and rejection in groups. Group Process. Intergroup Relat. 20, 693–706 (2017).

    Article  Google Scholar 

  3. 3.

    Robinson, S. L., O’Reilly, J. & Wang, W. Invisible at work: an integrated model of workplace ostracism. J. Manage. 39, 203–231 (2013).

    Google Scholar 

  4. 4.

    Williams, K. D. & Nida, S. A. Ostracism and public policy. Policy Insights Behav. Brain Sci. 1, 38–45 (2014).

    Article  Google Scholar 

  5. 5.

    Blackhart, G. C., Eckel, L. A. & Tice, D. M. Salivary cortisol in response to acute social rejection and acceptance by peers. Biol. Psychol. 75, 267–276 (2007).

    Article  PubMed  Google Scholar 

  6. 6.

    Eisenberger, N. I., Lieberman, M. D. & Williams, K. D. Does rejection hurt? An FMRI study of social exclusion. Science 302, 290–292 (2003).

    Article  PubMed  CAS  Google Scholar 

  7. 7.

    Wesselmann, E. D., Nairne, J. S. & Williams, K. D. An evolutionary social psychological approach to studying the effects of ostracism. J. Soc. Evol. Cult. Psychol. 6, 309–328 (2012).

    Article  Google Scholar 

  8. 8.

    Sasaki, T. & Uchida, S. The evolution of cooperation by social exclusion. Proc. R. Soc. B 280, 2012 (2012).

    Article  Google Scholar 

  9. 9.

    Kurzban, R. & Leary, M. R. Evolutionary origins of stigmatization: the functions of social exclusion. Psychol. Bull. 127, 187–208 (2001).

    Article  PubMed  CAS  Google Scholar 

  10. 10.

    Gruter, M. & Masters, R. D. Ostracism as a social and biological phenomenon: an introduction. Ethol. Sociobiol. 7, 149–158 (1986).

    Article  Google Scholar 

  11. 11.

    Nakamaru, M. & Yokoyama, A. The effect of ostracism and optional participation on the evolution of cooperation in the voluntary public goods game. PLoS ONE 9, e108423 (2014).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  12. 12.

    Johnson, T. The strategic logic of costly punishment necessitates natural field experiments, and at least one such experiment exists. Behav. Brain Sci. 35, 31–32 (2012).

    Article  PubMed  Google Scholar 

  13. 13.

    Bowles, S. & Gintis, H. The evolution of strong reciprocity: cooperation in heterogeneous populations. Theor. Popul. Biol. 65, 17–28 (2004).

    Article  PubMed  Google Scholar 

  14. 14.

    Wesselmann, E. D., Wirth, J. H., Pryor, J. B., Reeder, G. D. & Williams, K. D. When do we ostracize? Soc. Psychol. Personal. Sci. 4, 108–115 (2013).

    Article  Google Scholar 

  15. 15.

    Guala, F. Reciprocity: weak or strong? What punishment experiments do (and do not) demonstrate. Behav. Brain Sci. 35, 1–15 (2012).

    Article  PubMed  Google Scholar 

  16. 16.

    Boehm, C. et al. Egalitarian behavior and reverse dominance hierarchy [and Comments and Reply]. Curr. Anthropol. 34, 227–254 (1993).

    Article  Google Scholar 

  17. 17.

    Hirshleifer, D. & Rasmusen, E. Cooperation in a repeated prisoners’ dilemma with ostracism. J. Econ. Behav. Organ. 12, 87–106 (1989).

    Article  Google Scholar 

  18. 18.

    Feinberg, M., Willer, R. & Schultz, M. Gossip and ostracism promote cooperation in groups. Psychol. Sci. 25, 656–664 (2014).

    Article  PubMed  Google Scholar 

  19. 19.

    Maier-Rigaud, F. P., Martinsson, P. & Staffiero, G. Ostracism and the provision of a public good: experimental evidence. J. Econ. Behav. Organ. 73, 387–395 (2010).

    Article  Google Scholar 

  20. 20.

    Cinyabuguma, M., Page, T. & Putterman, L. Cooperation under the threat of expulsion in a public goods experiment. J. Public Econ. 89, 1421–1435 (2005).

    Article  Google Scholar 

  21. 21.

    Davis, B. J. & Johnson, D. B. Water cooler ostracism: social exclusion as a punishment mechanism. East. Econ. J. 41, 126–151 (2015).

    Article  Google Scholar 

  22. 22.

    Hales, A. H., Kassner, M. P., Williams, K. D. & Graziano, W. G. Disagreeableness as a cause and consequence of ostracism. Pers. Soc. Psychol. Bull. 42, 782–797 (2016).

    Article  PubMed  Google Scholar 

  23. 23.

    Kagel, J. & McGee, P. Personality and cooperation in finitely repeated prisoner’s dilemma games. Econ. Lett. 124, 274–277 (2014).

    Article  Google Scholar 

  24. 24.

    Wesselmann, E. D., Wirth, J. H., Pryor, J. B., Reeder, G. D. & Williams, K. D. The role of burden and deviation in ostracizing others. J. Soc. Psychol. 155, 483–496 (2015).

    Article  PubMed  Google Scholar 

  25. 25.

    Wesselmann, E. D., Williams, K. D. & Wirth, J. H. Ostracizing group members who can (or cannot) control being burdensome. Hum. Ethol. Bull. 29, 82–103 (2014).

    Google Scholar 

  26. 26.

    Wirth, J. H., Bernstein, M. J. & LeRoy, A. S. Atimia: a new paradigm for investigating how individuals feel when ostracizing others. J. Soc. Psychol. 155, 497–514 (2015).

    Article  PubMed  Google Scholar 

  27. 27.

    Williams, K. D. Ostracism: the kiss of social death. Soc. Personal. Psychol. Compass 1, 236–247 (2007).

    Article  Google Scholar 

  28. 28.

    Nezlek, J. B., Wesselmann, E. D., Wheeler, L. & Williams, K. D. Ostracism in everyday life. Group Dyn. 16, 91–104 (2012).

    Article  Google Scholar 

  29. 29.

    Yang, J. & Treadway, D. C. A social influence interpretation of workplace ostracism and counterproductive work behavior. J. Bus. Ethics 148, 879–891 (2018).

    Article  Google Scholar 

  30. 30.

    Nezlek, J. B., Wesselmann, E. D., Wheeler, L. & Williams, K. D. Ostracism in everyday life: the effects of ostracism on those who ostracize. J. Soc. Psychol. 155, 432–451 (2015).

    Article  PubMed  Google Scholar 

  31. 31.

    Holland, J. Emergence: From Chaos to Order (Addison-Wesley, Redwood City, CA, 1998).

  32. 32.

    Sommer, K. L., Williams, K. D., Ciarocco, N. J. & Baumeister, R. F. When silence speaks louder than words: explorations into the intrapsychic and interpersonal consequences of social ostracism. Basic Appl. Soc. Psych. 23, 225–243 (2001).

    Article  Google Scholar 

  33. 33.

    Rand, D. G., Arbesman, S. & Christakis, N. A. Dynamic social networks promote cooperation in experiments with humans. Proc. Natl Acad. Sci. USA 108, 19193–19198 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  34. 34.

    Shirado, H., Fu, F., Fowler, J. H. & Christakis, N. A. Quality versus quantity of social ties in experimental cooperative networks. Nat. Commun. 4, 2814 (2013).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  35. 35.

    Wang, J., Suri, S. & Watts, D. J. Cooperation and assortativity with dynamic partner updating. Proc. Natl Acad. Sci. USA 109, 14363–14368 (2012).

    Article  PubMed  PubMed Central  Google Scholar 

  36. 36.

    Barclay, P. Biological markets and the effects of partner choice on cooperation and friendship. Curr. Opin. Psychol. 7, 33–38 (2016).

    Article  Google Scholar 

  37. 37.

    Skyrms, B. & Pemantle, R. A dynamic model of social network formation. Proc. Natl Acad. Sci. USA 97, 9340–9346 (2000).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  38. 38.

    Page, S. E. Path dependence. Quart. J. Polit. Sci. 1, 87–115 (2006).

    Article  Google Scholar 

  39. 39.

    Zadro, L., Williams, K. D. & Richardson, R. How low can you go? Ostracism by a computer is sufficient to lower self-reported levels of belonging, control, self-esteem, and meaningful existence. J. Exp. Soc. Psychol. 40, 560–567 (2004).

    Article  Google Scholar 

  40. 40.

    Grimm, V. et al. Pattern-oriented modeling of agent-based complex systems: lessons from ecology. Science 310, 987–991 (2005).

    Article  PubMed  CAS  Google Scholar 

  41. 41.

    Smith, E. R. & Conrey, F. R. Agent-based modeling: a new approach for theory building in social psychology. Pers. Soc. Psychol. Rev. 11, 87–104 (2007).

    Article  PubMed  Google Scholar 

  42. 42.

    Rescorla, R. A. & Wagner, A. in Classical Conditioning II: Current Research and Theory (eds Black, A. H. & Prokasy, W. H.) 64–99 (Appleton-Century-Crofts, East Norwalk, CT, 1972).

  43. 43.

    Rubinstein, A. Finite automata play the repeated prisoner’s dilemma. J. Econ. Theory 39, 83–96 (1986).

    Article  Google Scholar 

  44. 44.

    Palminteri, S., Wyart, V. & Koechlin, E. The importance of falsification in computational cognitive modeling. Trends Cogn. Sci. 21, 425–433 (2017).

    Article  PubMed  Google Scholar 

  45. 45.

    Steingroever, H., Wetzels, R. & Wagenmakers, E.-J. Absolute performance of reinforcement-learning models for the Iowa Gambling Task. Decision 1, 161–183 (2014).

    Article  Google Scholar 

  46. 46.

    Erev, I. & Roth, A. E. Predicting how people play games: reinforcement learning in experimental games with unique, mixed strategy equilibria. Am. Econ. Rev. 88, 848–881 (1998).

    Google Scholar 

  47. 47.

    Lindström, B. & Olsson, A. Mechanisms of social avoidance learning can explain the emergence of adaptive and arbitrary behavioral traditions in humans. J. Exp. Psychol. Gen. 144, 688–703 (2015).

    Article  PubMed  Google Scholar 

  48. 48.

    Zaki, J., Kallman, S., Wimmer, G. E., Ochsner, K. & Shohamy, D. Social cognition as reinforcement learning: feedback modulates emotion inference. J. Cogn. Neurosci. 28, 1270–1282 (2016).

    Article  PubMed  Google Scholar 

  49. 49.

    Hartgerink, C. H. J., van Beest, I., Wicherts, J. M. & Williams, K. D. The ordinal effects of ostracism: a meta-analysis of 120 cyberball studies. PLoS ONE 10, e0127002 (2015).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  50. 50.

    Janssen, I., Craig, W. M., Boyce, W. F. & Pickett, W. Associations between overweight and obesity with bullying behaviors in school-aged children. Pediatrics 113, 1187–1194 (2004).

    Article  PubMed  Google Scholar 

  51. 51.

    Knecht, A., Snijders, T. A. B., Baerveldt, C., Steglich, C. E. G. & Raub, W. Friendship and delinquency: selection and influence processes in early adolescence. Soc. Dev. 19, 494–514 (2010).

    Article  Google Scholar 

  52. 52.

    van Duijn, M. A. J., Zeggelink, E. P. H., Huisman, M., Stokman, F. N. & Wasseur, F. W. Evolution of sociology freshmen into a friendship network. J. Math. Sociol. 27, 153–191 (2003).

    Article  Google Scholar 

  53. 53.

    Van De Bunt, G. G., Van Duijn, M. A. J. & Snijders, T. A. B. Friendship networks through time: an actor-oriented dynamic statistical network model. Comput. Math. Organ. Theory 5, 167–192 (1999).

    Article  Google Scholar 

Download references


We thank C. Efferson for valuable suggestions regarding the design and implementation of experiment 1, and A. Olsson, P. Pärnamets and I. Selbing for comments on an earlier version of the manuscript. This research was supported by Swiss NSF grants PP00P1_150739, 00014_165884 and 100019_176016 to P.N.T. B.L. was supported by Forte (COFAS2: 2014-2785 FOIP). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Author information




B.L. and P.N.T. conceived the study and designed the experiments. B.L. collected the data, developed the models, analysed the data and implemented the models. B.L. and P.N.T. wrote the paper.

Corresponding author

Correspondence to Björn Lindström.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Methods, Supplementary Notes 1–2, Supplementary Figures 1–10, Supplementary Tables 1–9, Supplementary References 1–16

Reporting Summary

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Lindström, B., Tobler, P.N. Incidental ostracism emerges from simple learning mechanisms. Nat Hum Behav 2, 405–414 (2018).

Download citation

Further reading


Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing